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by: Mitchell Schulist


Mitchell Schulist
Texas A&M
GPA 3.83

Linda Talley

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Linda Talley
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This 40 page Class Notes was uploaded by Mitchell Schulist on Wednesday October 21, 2015. The Class Notes belongs to NUTR 202 at Texas A&M University taught by Linda Talley in Fall. Since its upload, it has received 40 views. For similar materials see /class/226095/nutr-202-texas-a-m-university in Nutrition and Food Sciences at Texas A&M University.

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Date Created: 10/21/15
Review Exam 3 Nutrition and You Nutrition and Fitness 10 Fitness characteristics that enable body to perform physical activity Components includes Cardiorespiratory heart amp lungs performance Muscle strength resistance ability to produce force Muscle endurance ability to work over a period of time Flexibility range of motion Body composition proportion of muscle fat water amp other tissues Regular activity promotes health and prevents disease Fitness provides numerous bene ts Less chronic disease Better sleep Reduced stress amp depression Improved body composition Improved bone health Improved immune system More endorphins feel good brain chemicals Cardiorespiratory aerobic training increases blood propulsion amp oxygen while decreasing pulse amp blood pressure Stroke volume is the amount of oxygenated blood propelled to tissues with each heartbeat V02 max aerobic capacity ability of cardiovascular system to deliver oxygen to the body Weight training builds lean body mass improving strength endurance amp BMR Exercise improves weight management increases energy needs promotes loss of body fat maintains lean body mass Everyone should participate in 3060 minutes of moderate activity 57 days per week Complete fitness includes Aerobic exercise for cardiovascular conditioning 6085 maximum heart rate Strength and endurance training to increase muscle mass Stretching before and after exercise helps warm up and cool down muscle and prevents injury and improves flexibility Find an exercise you enjoy or recruit a buddy Start slowly but make it fun and convenient be persistent and be safe Carbohydrate can make energy anaerobically without oxygen for a short period of time Protein and fat require oxygen to burn aerobic metabolism Energy Systems of Activity Adinosine Triphosphate ATP gives instant energy can be anaerobic Creatine phosphate breaks down to ATP Glucose amp Glycogen yield energy till limited supplies are exhausted Fats must have oxygen aerobic to make energy and are used primarily after about 20 minutes of activity Fuel mix depends on diet intensity duration and training for activity Glycogen Carbohydrate Loading Supercompensation uses high complex carbohydrate diet especially after endurance activity amp can make muscles adapt by creating more mitochondria to store more glycogen in muscle and liver for next activity period When glucose breakdown occurs at a high rate lactic acid will be produced and it can lower pH of the blood creating discomfort Works best for endurance sports and may actually be a disadvantage for sports less than 90 minutes Liver can clear lactic acid from the blood and convert it back to carbohydrate for fuel Once athletes deplete muscle and liver glycogen they may Hit the Wall or Bonk which is an ovenNhelming fatigue that affects brain too Carbohydrate is the primary fuel during highintensity activity Fat is the primary fuel during low to moderate activity sustained over time but requires oxygen to burn it Training applies the progressive overload principle putting demand on muscles to make them adapt by getting stronger Athletes need more protein to repair and build muscle but usually eat more food thus get more protein Diet should supply nutrients when they are most needed Fuel is needed before during and after exercise Large meals take 34 hours to digest Snacks and fluids may be gone in 1 hour Sports drinks are bene cial for activities lasting longer than 1 hour and may be especially bene cial for endurance athletes They provide fluid electrolytes and easily absorbed carbohydrate After exercise complex carbohydrates with some protein are beneficial Supplemental vitamins and minerals help performance only if there was a deficiency Antioxidant vitamins A E and C help prevent oxidative stress but supplements have not been proven to help Calcium is important to prevent bone damage assist muscle contraction nerve transmission blood clotting and hormone activity Iron is important especially for female athletes and runners Sports anemia can develop when training starts and there is more need of red blood cells to carry oxygen but usually selfcorrects without iron supplements after 6 weeks Female Athlete Triad or Anorexia Athletica Athletes in weight dependent sports engage in restrictive eating and excessive exercise to maintain thin bodies leading to low body fat low estrogen levels amenorrhea osteoporosis amp stress fractures that won t heal ending competitive careers Also see this with some males wrestling skating gymnastics First sign of dehydration is fatigue quotWaterquot is the most important nutrient for active bodies and all others Dehydrated body is at a disadvantage to produce optimum energy Even 13 weight loss due to water loss severely impairs performance Water lost in activity must be replaced Electrolytes and salt are generally not needed except perhaps in endurance activities Caffeine and alcohol have diuretic effects so water is best choice Fruit juices may need dilution as some have too much sugar Carbonated beverages may cause bloating and gas Hyperthermia amp heatstroke develop from too much heat Symptoms are headache nausea dizziness confusion amp either excessive or insufficient sweating Athlete needs cool uid amp environment Hypothermia develops in cold weather Symptoms are shivering euphoria weakness amp apathy Athlete needs warm fluid amp environment Hyponatremia low blood sodium may develop from drinking too much water too fast Pregame meals should be light carbohydrate rich but low ber amp easy to digest Postgame meals should be high complex carbohydrate amp fluid rich Many ergogenic aids used to enhance athletic performance are not particularly effective and may have serious side effects or be banned Creatine may help improve muscle mass but studies have had mixed results Carnitine is made in body and supplements have not been proven effective Caffeine is a stimulant but is banned in high amounts by some Athletic Associations Anabolic Steroids build muscle but have many undesirable side effects such as hormone problems and aggressiveness and are illegal Growth Hormone increases muscle mass but not strength can cause acromegaly abnormally large tissues and organs Erythropoietin blood doping to increase oxygen carrying capacity can increase blood viscosity causing heart attacks and strokes Sports bars shakes and meal replacements are convenient but very expensive Many other supplements have been marketed to athletes as magic bullets but most have not been proven effective in well controlled studies Proper diet and activity produces good health and optimum performance Adequacy variety balance and moderation are best Nutrition During Pregnancy and lnfancy 11 Pregnancy usually about 40 weeks long divided into trimesters Before conception both mother and father need healthy habits to create a healthy baby Woman is especially responsible for keeping herself and baby healthy First trimester baby is developing many types of body tissues nutrition is especially critical This is most critical period in pregnancy forthe baby Embryo 28 weeks of developing baby Fetus 9 weeks to 9 months 40 weeks of developing baby before delivery Placenta organ developed in uterus that produces hormones and transfers nutrients and waste materials between mother and baby without exchanging blood supplies Brain and spinal column form neural tube the rst 6 weeks it is especially important and needs plenty of folate but mother may not even know that she is pregnant Proper weight at conception for mother is helpful OvenNeight women tend to have too large babies macrosomia UndenNeight women tend to have too small babies with multiple problems Excessive caffeine consumption also can cause problems Smoking alcohol drugs and some supplements can also cause birth defects During first trimester women should eat normally but may experience morning sickness Pregnant women can and should exercise but be careful about weight impact balance falls intensity and fatigue 30 minutes per day of moderate activity is good Weight gain for entire pregnancy is usually recommended at 1540 pounds with 2535 considered normal for normal weight women Folate Zinc and Iron are especially necessary and a prenatal supplement may be needed to achieve recommended amounts Vegetarians need to be especially careful of Omega 3 Linolenic fatty acids Vitamin B12 protein and Calcium ln second trimester both mother and baby grow larger requiring an extra 340 calories about 1 serving from each food group from nutrient dense foods Daily exercise with low impact activities is good for stress and sleep Potential complications Gestational diabetes elevated blood glucose usually goes away with delivery but mother may be at elevated risk of Type 2 Diabetes Hypertension may damage kidneys and other organs Eclampsia hypertension with edema swelling and protein in urine is especially dangerous for mother and baby typically occurs in second half of pregnancy Third trimester woman will gain about 1 pound per week with 450 extra calories per day about 1 serving per food group extra needed Healthy baby will weigh about 7 pounds at birth weight and length are primary health indicators Mothers may be more comfortable eating small frequent meals with an emphasis on fiber and fluid to prevent constipation many organs crowded Food cravings and Pica abnormal compulsive intake of nonfood items like clay and laundry starch may occur Commonly associated with anemia but cause is not clear Increased risk factors associated with pregnancy Critical periods Teratogens chemicalscause birth defects Pregnant women should not consume excessive arti cial sweeteners not much research on long term effects yet Too much Vitamin A can cause birth defects like cleft palate split roof of mouth kidney problems and nerve damage Avoiding foodborne illness from pathogens is important Lysteria monocytogenes grows at refrigeration temperatures and causes birth defects and stillbirths should be avoided Toxoplasmosis from handling infected cat feces can be a parasite problem Malnutrition can cause low birth weights and growth retardation Poverty is a risk factor Poor maternal health can cause subsequent problems Pregnant teenagers face special problems since mother is still growing and maturing while baby is developing Unmarried pregnant teen agers is a public health issue costing lots of money and misery Delaying pregnancy till over 35 may also cause more complications and birth defects especially Down Syndrome a chromosomal abnormality Pregnancies with multiples frequent ones or high risk pregnancies can all cause problems Women of childbearing age should be careful of methylmercury issues from consumption of large sh which can cause birth defects Alcohol consumption can cause irreversible Fetal Alcohol Syndrome and retardation mother should refrain from alcohol while pregnant Cigarette Smoking may lead to Sudden Infant Death Syndrome Many drugs both legal and illegal can cause problems check with Doctor before using any drugs WIC Women Infants and Children is a supplemental federal program that provides extra food for pregnant women and children till age 5 Lactation or breastfeeding is best for baby Sucking stimulated hypothalamus in brain which stimulates release of Prolactin triggers milk production Oxytocin triggers milk to letdown response Colostrum is first breastfluid after birth and has lots of immunity factors as well as nutrient dense food for very small tummies Breast milk is specially formulated for babies and changes composition as babies age to match their nutritional needs Breast milk promotes good brain development and bonding with the mother It is inexpensive sterile and very convenient Mother uses 500900 calories per day for nursing much comes from stored fat nursing mothers need about 1 liter extra water per day If breast milk is to be stored it should be handled carefully and refrigerated or frozen promptly Milk is the primary food for the first 6 months of life Alcohol caffeine and drugs can pass through mother s milk Some foods can cause gas in the baby Formula is an attempt to copy breastmilk and FDA regulates it AIDS mothers and Glactosemia can t break down glactose babies should not nurse Cow s milk is the basis of most formulas though soymilk is available Hypoallergenic formulas are available to avoid cow or soy milks Formula should be iron fortified as milk is a poor source of iron Formula handling must be sanitary to avoid illness From birth to first birthday a healthy infant will triple its birth weight thus nutrient needs are high to compensate for rapid growth rate Because of small tummies infants need very nutrient dense diets Lots of brain and social development also occurs Infant height weight and development should be charted to indicate any possible problems Infant needs single dose of Vitamin K at birth because of sterile GI tract to prevent excessive bleeding Infant also needs Iron Vitamin D and possibly Fluoride and may need supplemental drops to obtain these Toxicity with supplements is possible Iron poisoning from excessive supplement intake is most common poisoning of small children Diarrhea is more dangerous with small children due to limited fluid reserves Mashed solid foods are introduces at 46 months as babies can handle them They should be introduced 1week to detect possible allergies Choking should be avoided cutting food into small bites may help with this or avoiding the worst ones such as carrots grapes and hot dogs Rice cereals are usually first food introduced due to lack of allergies Food allergies may not show during first exposure but if antibodies develop 2nd exposure may cause mast cells to rupture releasing histamine and triggering an allergic reaction hives swelling itching cramps diarrhea decreased blood pressure and may even be fatal Peanuts are most common serious allergy Baby foods do not need seasonings Rule of thumb for feeding is 1 Tablespoon of food per meal offered per year of age for mashed foods and offer a variety at each meal to cover good nutrition Too much milk orjuice may replace other needed nutritious foods Babies should not be put to bed with bottle as they may develop nursing bottle syndrome decay of upper teeth Honey may carry Clostridium botulinum food poisoning Nutrition from 1 to 100 12 Toddlers 13 and Preschoolers 35 growth rates slow from infants gaining from 35 pounds and a few inches height per year Appetites diminish as they become interested in activities and exercise more thus they need very nutrient dense food Small tummies mean that they need small frequent meals and snacks Portion size rule of thumb is 1 Tablespoon of food for each year up to age 5 Solid foods should be cut small to prevent choking Before 2 fat should not be cut since much is needed for nerve tissue development but after 2 cut in fat may be needed to prevent obesity and chronic disease development Children with allergies may need to have daycare or school provided with special foods Children especially need Calcium and Vitamin D and Iron due to rapid growth rates Children also have problems with getting enough Vitamin D and Fiber Children need nutrient dense fluids like milk and juice but can get too much Picky eating and food jags eating limited selection are common Parents provide selection but children should be allowed to choose amount and refuse foods New foods may need to be offered 10 or more times before kids will eat it School age children are growing more rapidly again and establishing many nutrition habits Childhood obesity is growing problem due to calorie dense foods and too little physical activity Today s children may not live as long as their parents Chronic diseases are arising at earlier ages due to poor health habits Dental decay is associated with high sugar intake but Attention Deficit Hyperactivity Disorder has not been documented in controlled studies My Pyramid of Kids can help plan a healthy diet and activity pattern it is same as adult pyramid but portion sizes are smaller Federally funded School Lunch and Breakfast Programs provide significant nutrition for many children especially in low income areas Children learn and behave better with proper nutrition and breakfast Children often need more nutrient density and less screen time thus more physical activity Lead toxicity is a problem especially if children live in older homes with lead in paint or near industrial areas that have lead in soil and water Lead displaces proper minerals like Iron Zinc and Copper but does not do their functions Adolescence Puberty corresponds with another growth spurt and many hormonal changes These kids control more ofthe foods they consume Girls exposed to high fat diets start menarche menstruation earlier Parttime jobs and having their own transportation accelerates changes There is more influence from peers and the media Sometimes they adopt unhealthy habits Adolescents still need lots of calcium for bone growth girls especially drink too many diet sodas and not enough milk setting them up for low bone mass Boys and girls both need lots of Iron and with menstruation onset girls actually need more iron than boys Fast foods can fit in the diet but choices should be lower fat and calories or less frequent than usual Vegetarian diets can be healthy but should also be well chosen Special concerns for teens Adolescents are at high risk of developing eating disorders especially female athlete triad Athletic teens may compromise health with inappropriate ergogenic aids Many teens start tobacco habits Some teens start alcohol habits especially binge drinking that can cause multiple problems alcohol does have 7 calories per gram and alters nutrient absorption and metabolism Old folks need high nutrient density diets as they are living longer w ant them to live healthier too as that is more cost effective Life expectancy is increasing and older populations require more health care Factors affecting aging Environment disease accidents toxins Genetics susceptibility to stress and ability to repair damage Life style nutrition exercise and reaction to stress Calorie needs drop about 10 per each 10 years of life but nutrient needs continue to be high They need more fiber and fluid but often consume less Dehydration is a huge issue as thirst is unreliable and kidney function is not as efficient Too much Vitamin A can contribute to osteoporosis Vitamin D becomes an issue Skin looses ability to convert cholesterol to Vitamin D Kidneys loose ability to absorb and convert it to active form Intestines loose ability to absorb it and Calcium Stomach produces less acid and intrinsic factor creating problems with Vitamin B12 deficiency plenty of folate and B12 can reduce homocysteine levels lowering risk of heart attack Iron Zinc and Calcium are usually issues with older adults Eating right is good for disease prevention Older adults gain fat even if not weight thus changing body composition They become more frail with weakness mobility and balance issues The immune system declines Phytochemicals and antioxidants are important for older adults Staying physically active improves body composition and health but most older adults are not very physically active Arthritis inflammation ofthe joints often decreases exercise Osteoarthritis can be improved with proper exercise Rheumatoid arthritis seems improved some with the Mediterranean Diet Alzheimers Disease dementia may be due to free radicals and inflammation Macular degeneration and cataracts cause vision problems Many older adults take multiple medications and may have interactions or status changes that affect effectiveness of medications Food insecurity can be a problem for many elderly due to Insufficient income Lack of transportation Depression is more common with loss of spouses friends jobs income Alcohol abuse can also cause problems unfortunately it is not an effective treatment for most problems Federally funded Congregate meals are available free at Senior Citizens Centers or may be delivered by Meals on Wheels volunteers Assisted living may be required by some elderly Physical activity can be very beneficial Prevention of problems through healthy habits is more cost effective than treatment Alcohol Serving size is 5 oz wine or 12 oz of beer or 15 oz of hard liquor providing 7 calories lgm of alcohol Moderate drinking is no more than 1 drink day for women and 2 for men Women have less alcohol dehydrogenase ADH to process alcohol than men of the same size and they have less water to dilute it Ethanol is a very small molecule that is absorbed rapidly and effects are very fast Food in stomach delays and slows the rate of absorption Ethanol is a toxin and must be eliminated quickly so the liver gives it metabolic priority over food Alcohol is a diuretic ADH and microsomal ethanoloxidizing system MEOS which also metabolizes other drugs control the metabolism of ethanol Short term effects Excess alcohol can accumulate in blood stream and can cause alcohol poisoning and even death Alcohol can cause amnesia Alcohol affects reaction time making driving underthe influence dangerous Alcohol affects judgment Alcohol is a factor in 40 of all traffic fatalities Longer term effects Alcoholism seems some genetic and is more common in those who start drinking at a young age Liver can suffer developing fatty deposits and alcoholic hepatitis which may be reversed if drinking stops Liver can eventually develop cirrhosis which cannot be reversed and may be fatal Benefits of drinking alcohol Moderate consumption may reduce risk of heart disease and stroke Raises blood levels of HDL if moderate Phytochemicals in red wine may be cardioprotective Alcohol should be consumed slowly no more than 1 drink per hour and a half How Safe is Our Food Supply 13 Foodborne illness from bacteria is 1 76 million casesyear 325000 hospitalizations and 5000 deaths estimated primary concern of regulators Upton Sinclair s 1906 book The Jungle about the filthy meatpacking industry in Chicago led to the first US food Laws CDC Center for Disease Control monitors foodborne illness FDA Food and Drug Agency ensures processed foods safety USDA US Department of Agriculture ensures meat poultry and egg safety EPA regulates pesticides and water quality NMFS National Marine Fisheries has voluntary inspection of fish NOAA National Oceanic and Atmospheric Administration inspects seafood ATF Alcohol Tobacco and Firearms regulates and inspects Alcohol production International and local agencies also regulate and inspect food production facilities Toxicity is determined by dose and toxicity ofthe compound or microbe consumed It may also depend on the size diet and health ofthe recipient Children and old folks are higher risk populations National Food Safety Initiative seeks to reduce foodborne illness by improving practices from the farm to the fork and coordinating the efforts of Federal Agencies HACCP Hazard Analysis Critical Control Point is a foodborne illness prevention system designed to improve food safety in US It is enforced by both FDA and USDA Imported foods are not as well inspected thus are a concern 1 Conduct hazard analysis 2 Identify critical control points 3 Establish critical limits 4 Establish monitoring procedures 5 Establish corrective action 6 Keep records 7 Verification procedures Currently many foodborne illnesses are caused by consumers in their homes practice careful handling and storage procedures Pathogens bacteria viruses and molds cause illness in humans Numerically bacteria are the primary concern FecaltooraItransmission is a common cause of pathogen exposure wash hands well Foodborne infection microbes set up and grow in GI tract may take a few days to develop illness so often under diagnosed Salmonella is common in raw meats poultry amp eggs most common foodborne illness in US causinf flulike symptoms a couple of days later Campylobacteris common fecaltooral causing diarrhea can cause GuillainBarre Syndrome where immune system attacks own nerves and causes paralysis Traveler s diarrhea is primarily from Eschericia coli Take antibiotic amp antidiarrhea drugs when traveling internationally It is also wise to avoid raw fruits and vegetables as well as undercooked meats Avoid street vendors without proper sanitation Drink only properly treated water Food Intoxication Microbes produce toxin that causes illness when consumed rapid onset and often noticed quickly due to vomiting and diarrhea Clostridium botulinum is most deadly intoxication causes respiratory shutdown up to 60 fatal may occur in improperly canned foods Staphlococcus areus is most common intoxication causing vomiting and diarrhea common in nasal passages and spread by coughing and sneezing not usually fatal EColi O157H7 from healthy cattle is an Intoxification caused Jack in the Box illness that may contaminate meat or vegetables causing hemolytic uremia and damaging GI tract and kidneys and causes death in some people especially young and old Viruses require a living host their genetic material produces more viruses in victims cells do not grow and reproduce in food itself common cause is undercooked seafood proper cooking will kill them Norovirus can cause gastroenteritis stomach flu Hepatitis A can cause infection and liver disease Hepatitis can also be transmitted in raw or undercooked seafood Some mold is used to develop avors and odors in food or to develop medicine blue cheese and penicillin Other mold can be toxic Aspergillis in peanuts can cause liver disease Parasites like Cyclospora Giardia Cryptosporum and Trichinella can also be problems if undercooked foods are consumed Some parasites are destroyed when fish is frozen Bovine Spongioform Encephalopathy BSE Mad Cow Disease is caused by prions in contaminated feed and has severely damaged the British Cattle Industry Variant CreutzfeldtJacob Disease is human form and may lead to dementia and death in about 14 months and may be transmitted by brain and nervous tissue consumption rare disease Customer awareness is important to control Wash hands thoroughly and often Wash foods and utensils and surfaces well Avoid crosscontamination Observe Safe Handling Instructions Keep clean safe kitchen Avoid crosscontamination Cook meats thoroughly thermometer Thaw meats in refrigerator Keep hot foods hot Keep cold foods cold When in doubt throw it out Bacteria grow best at 40140 F danger zone Heat and cool rapidly through the danger zone cool in shallow containers Use a thermometer to be sure food are cooked thoroughly Leftovers should not be out longer than 2 hours 40 s to prevent foodborne illness Clean thoroughly Combat cross contamination especially raw and cooked foods Cook thoroughly meats 160 F Chill promptly and thoroughly to 40 F Environmental contaminants Heavy metals mercury and lead there is more mercury accumulation of large fish due to longer exposure Carcinogens Polychlorinated biphenyls Persistence don t break down Bioaccumulation larger concentrations as they move up food chain Naturally occurring toxicants small doses don t really seem problem Young children with underdeveloped immune systems and old or diseased cancer people are at greatest risk with these problems Hormones are added to increase food yields and are not a problem when used properly Recombinant bovine somatotrophin rBST produces up to 25 more milk but hormones are broken down to amino acids in GI tract Antibiotics are added to prevent animal disease in space intensive production facilities but do contribute to antibiotic resistant bacteria which is a problem Pesticides are used to produce greater quantity better quality of food most are not a problem when used properly but cause great consumer concern EPA sets standards and USDA and FDA enforce them Integrated Pest Management is alternative in production economical and least harmful but not often labeled as such Washing and pealing produce minimizes exposure Organic Food production is more free of pesticides but also more expensive and may not be any more nutritious Nutritional adequacy concerns Minimize losses of vitamins in cooking amp storage exposure to time oxygen heat may inactivate them Food Preservation Industry uses many techniques to protect food from the farm to the table including Pickling acid ampor salt Pasteurization heat to kill pathogens Drying RefrigerationFreezing Canning kill spores and pathogens Modified Atmosphere Packaging remove oxygen to delay decay High temperatures on grill may cause Polycyclic hydrocarbons PHA s and Heterocyclic amines HCA s which are carcinogenic following cooking instructions should minimize those Acrylamide formed during high temperature baking and frying may also be a concern Advances in processing include Irradiation is major cold pasteurizationsterilization method but consumers still have concerns lt inhibits DNA of bacteria but does not destroy viruses Foods must have green Radura label High intensity pulsed light High pressure systems Modified Atmosphere Packaging MAP prevents oxygen from ripening or causing deterioration of food in package eliminating extreme heat or cold made prepackaged salads and entrees possible Code Dating helps with inventory control and rotation Closed coded dating known only to manufacturer Open dating easily interpreted by customer Additives must be effective detectable and safe require much testing by manufacturer which must prove them safe to FDA GRAS Generally Recognized as Safe or Prior Sanctioned Substances extensive long term use determined to be safe Delaney Clause zero risk for carcinogens controversial now but FDA uses negligible risk policy more recently Evaluates Risk versus Benefit Intentional or Direct Food Additives have many uses regulated by FDA Indirect additives accidental like packaging material migration during heating Water for drinking and washing must be safe and potable Surface water subject to contamination but easily treated 02 amp light Ground water harder to treat and many individual wells fragmented control amp not exposed to 02 amp light Home water treatment systems are not regulated Bottled water should be refrigerated after opening subject to contamination is regulated by FDA Some individuals may be sensitive to speci c additives like MSG monosodium glutamate or sulfites or color additives but labels have to speci cally identify these so read labels Toxins can occur naturally or be added to foods Natural toxicants can include Solanine in potatoes or Cyanide in lima beans or apricot pits at low levels most are not a problem Biotechnology promises many benefits faster than selective breeding but still controversial regulated by FDA Genetic Engineering produces Genetically Modified Organisms GMO s by removing a desired gene and placing it in another DNA recombinant DNA strand producing Transgenetic organisms higher yields and better quality Some consumers are concerned about GMO s especially Europe and Africa US does not seem as concerned and has many GMO s FDA rules for using Biotechnology UndesirabIe genetic modification product must be stable and tested Introduction of allergens must be labeled Excessive levels oftoxins can t be higher than naturally found Changes in nutrients must be equivalent to natural or tested extensively Creating of unknown new substances must be substantially equivalent Unsafe animal feeds tested like human foods Bioterrorism through food and water is possible but has been relatively rare processors and authorities are watching Hunger at Home and Abroad 14 Worldwide 1 in 8 is malnourished limiting physical amp mental energy more than 800 million affected Worldwide 6 million children under 5 die of undernutrition Worldwide overnutrition levels 1 billion are soaring too Cycle of malnutrition nutrient deficient pregnant women birth low weight babies susceptible to illness and death Even if children live they develop slowly not as completely and die of infectious diseases and even chronic diseases more commonly Nutrition Transition In many developing countries traditional diets are based on limited number of low quality plant foods As incomes rise energy dense foods become available and activity levels become less demanding Life expectancy increases but chronic disease also increases Food insecurity poor people who cannot afford nutritious food affects 34 million in U 8 alone many are children Food insecurity abroad affects over 2 billion 13 of world Causes of hunger Famine is a severe food shortage caused by drought ood pests or politics Poverty major one alcohol ampor drug abuse lack of education awareness about assistance amp resistance or pride Overpopulation occurs when a region has more people than resources can support Currently food production worldwide should be suf cient but is poorly distributed and population growth is proceeding faster than food production growth Using grain for energy will widen the gap Cultural practices may need to change ideas on what is acceptable or unacceptable food Limited environmental resources need to become better at managing renewable resources Poor quality diets in developing countries are often based on high ber grains with limited variety of other foods Common deficiencies are protein iron zinc seleniumcalcium iodine thiamine niacin and Vitamins A and C In US highest risk for hunger includes Household headed by single women Minority group Income below poverty level 12 of US population Children Intercity location Lack of desirable job skills Mental illness Physically disabled Homeless Elderly Poverty limits access to food and health care Lack of education is both a cause and consequence of poverty Poverty in Developing Countries is much worse than in U S affecting many Most affected are women amp children who spiral downward with malnutrition Discrimination against women children and elderly because they do not produce income is huge issue Persistent hunger or specific nutrient deficiency is a larger problem impacting morale and ability to work 40 of women suffer anemia Iron deficiency affecting morale ability to work and next generations 25 of children have Vitamin A de ciency which can affect vision immunity and membrane integrity 1 billion people regularly drink contaminated water Many have goiter due to lodine deficiency Marasmus protein energy malnutrition starvation is common among children in underdeveloped countries Kwashiorkor protein de ciency is also common among children Immunity is impacted negatively due to malnutrition protein vitamins amp minerals especially contributing to cholera dysentery and TB Many suffering from diarrhea and dehydration may be treated by Oral rehydration therapy a dilute solution of clean water sugar and salt World population is growing faster adding 70 millionyear than world food supply amp much housing increase occupies our most productive farm land Eliminating hunger is difficult but possible Provide short term aid but often surpluses from other countries and may not be well planned or executed to get to people most in need Control population growth main reason many poverty stricken people have many children is that few survive to adulthood and there is no one else to care of old folks as they age Economic and cultural factors Economic development improves outcomes and means children are not as needed for manual labor Education for women reduces birth rates Global hunger harms us all how can we eradicate hunger Biotechnology and better land management lncrease crop yields Precision agriculture match inputs to needs More salt amp drought resistant crop selections for less desirable land 15 Produce more foods lower on food chain ie less animals amp more plants in diet Animal foods require 200 more energy to produce than plant foods More energy efficient agriculture Education of farmers Proper Sanitation Food Water Sustainable agriculture choosing options that mesh well with local conditions Ways to increase food availability Improved economic development is needed to reduce poverty Forti cation of Foods that are shelf stable and affordable Education of consumers lmprove food safety amp eliminate waste Providing supplements may be cost effective in eliminating speci c deficiencies 15 of U S population receives some form of food assistance Federal Assistance Programs WIC Women Infants amp Children has been very cost effective for pregnant women and children till 5 School BreakfastLunch Program help older children with hunger Congregate amp Meals on Wheels for Senior Citizens Food Stamp Program USDA is the largest federal assistance program serves over 20 million people with average per capita expense of about 80mo Participants can only purchase food with assistance Food Recovery Programs Second Harvest is the largest U S national food recovery program Food Pantries Emergency amp Soup Kitchens Food Banks Nutrition education can help low income individuals stretch limited food dollars and produce safe foods Chapter 3 Digestion From Meals to Molecules The Organization of Life Begins with atoms that form molecules which are then organized into cells to form tissues organs and whole organisms o Atoms the smallest units of an element that retain the properties of the element 0 Molecules units oftwo or more atoms of the same or different elements bonded together 0 Cells the smallest units of life 0 Tissues made up of cells that are similar in structure and function Types oftissue muscle nerve epithelial and connective o Organs structures composed of more than one tissue that perform a specialized function 0 Organ system 11 organ systems interact to perform all the functions necessary for life An organ may be part of more than one organ system Q Hormone chemical messengers that are produced in one location in the body released into the blood and travel to other locations where they elicit responses The Digestive System Digestion the process by which food is broken down into components small enough to be absorbed into the body Mechanical or Chemical Digestion Absorption the process oftaking substances from the gastrointestinal tract into the interior of the body 0 Feces body waste including unabsorbed food residue bacteria mucus and dead cells Eliminated from the gastrointestinal tract Organs of the Digestive System Gastrointestinal tract hollow tube about 30 feet long 0 Also called gut GI tract alimentary canal or digestive tract Internal part of the GI is called lumen Organs of the GI include mouth pharynx esophagus stomach small intestine and large intestine You need to know the order ofthese organs as well as the names of some ofthe sphincters that are in between these organs Accessory organs salivary glands liver gall bladder and pancreas Transit time time it takes food to travel the length ofthe GI tract 2472 hours 0 Dependant on the composition of the diet level of physical activity emotional state health status and use of medications Digestive System Secretions Mucous viscous uid secreted by glands in the digestive tracts and other parts of the body Lubricates moistens and protects cells from harsh environments Enzymes protein molecules that accelerate the rate of speci c chemical reactions without themselves being changed Digestion and Absorption of Nutrients The Mouth Chemical and mechanical digestion begins in the mouth Saliva moistens food 0 Salivary amylase enzyme which begins the chemical digestion of foods containing carbohydrates Chewing mechanical breakdown of food The Pharynx Responsible for swallowing o Bolus chewed food mixed with saliva o Epiglottis connective tissue that covers the opening to the lungs during swallowing Also part of the respiratory system The Esophagus Connects the pharynx with the stomach Peristalsis coordinated muscular contractions that move material through the GI tract Esophageal Sphincter lower esophageal sphincter muscle that encircles the tube of the digestive tract and acts as a valve The Stomach Temporary storage place for food Chyme semiliquid food mass produced when a food bolus mixes with highly acidic stomach secretions Chemical digestion occurs 0 Gastric juice hydrochloric acid and pepsin Little absorption occurs Large meal takes longer than a liquid meal Solids take longerthan liquids o Nutritional composition Carbohydrates leave quickly Fiber and protein take longer High fat meal stays in the stomach the longest The Small Intestine Narrow tube about 20 feet long Main site for the chemical digestion of food Primary site for absorption of water vitamins minerals and the products of carbohydrate fat and protein digestion Secretions that aid digestion in the small intestine o Pancreas secretes pancreaticjuice contains bicarbonate Neutralizes the acid in the chime Makes the environment of the small intestine neutral or slightly basic 0 Pancreatic amylase enzyme that continues the breakdown of starch and sugars o Pancreatic proteases enzymes that breakdown protein to shorter chain amino acids 0 Lipases fat digesting enzymes 0 Gall bladder stores and secretes bile Liver produces bile Aids in fat digestion and absorption Absorption o Diffusion movement of substances from an area of high concentration to an area of lower concentration 0 Simple diffusion material moves freely across the cell membrane 0 Osmosis unassisted diffusion ofwater across the cell membrane 0 Facilitated diffusion a carrier molecule is needed for a substance to cross the cell membrane 0 Active transport requires energy and a carrier molecule Q Can transport material from an area of lower concentration to one of higher concentration The Large Intestine About 5 feet long Divided into the colon and the rectum Water and some vitamins and minerals can be absorbed in the colon Peristalsis occurs slowly Fecal material may spend 24 hours or more in the colon Intestinal microflora bene cial bacteria 0 Breakdown unabsorbed portions of food 0 This breakdown may produce gas which causes flatulence Rectum temporarily stores unabsorbed material until it is evacuated through the anus as feces Digestion in Health and Disease Celiac disease Location Small Intestine a protein gluten found in wheat barley and rye triggers an immune system response that damages or destroys the villi ofthe small intestine 0 Causes abdominal pain diarrhea and fatigue 0 Can lead to malnutrition weight loss anemia osteoporosis intestinal cancer and other chronic ailments 0 Also called gluten intolerance celiac sprue nontropical sprue gluten sensitive enteropathy o Diagnoses by a blood test or intestinal biopsy Heartburn and gastroesophageal reflux when the acidic contents of the stomach leak back into the esophagus Produces a burning sensation in the chest or throat GERD gastroesophageal reflux disease a chronic condition in which acidic stomach contents leak into the esophagus causing pan and damaging the esophagus o If left on treated can lead to bleeding ulcers and cancer 0 To avoid discomforts limit amounts and types of foods consumed eat small meals consume beverages between ratherthan with meals avoid fatty and fried foods chocolate peppermint and caffeinated beverages remain upright after eating wear loose clothing avoid smoking and alcohol lose weight Peptic Ulcers open sores in the lining ofthe stomach esophagus or upper small intestine 0 Causes GERD misuse of medications such as aspirin or nonsteroidal antiin ammatory drugs infection with the bacterium Helicobacter pylori H pylori H pylori can be treated with antibiotics Gallstones clumps of solid material that accumulate in either the gallbladder or the bile duct They can cause pain when the gallbladder contracts in response to fat in the intestineTreatment removal of the gallbladder Diarrhea and constipation common discomforts related to problems in the intestines o Diarrhea frequent water stools Q Can be caused by bacterial or viral infections irritants that inflame the lining of the GI tract the passage of undigested food into the large intestine medications and chronic intestinal diseases Causes loss of fluids and minerals Q Can be life threatening if lasting form more than a day or two 0 Constipation hard dry stools that are difficult to pass Occurs when the water content of the stool is too low Q Causes low intake ofwater or lack of fiber lack of exercise weakening of the muscles of the large intestine and a variety of medications Prevention drinking plenty of fluids consuming a high fiber diet and getting plenty of exercise What Should I Eat For Digestive Health Reduce your risk of adverse reactions o Read food labels to avoid foods that you are allergic to o Chew each bit thoroughly to maximize digestion and avoid choking 0 Don t talk with food in your mouth 0 Reduce the chances of heartburn 0 Eat enough to satisfy your hunger but not so much that you are stuffed 0 Wait 10 minutes between your rst and second courses to see how full you feel 0 Stay upright after you eat don t flop on the couch in front of the television Avoid constipation by consuming enough fiber and fluid 0 Choose wholegrain cereals such as oatmeal or raisin bran 0 Double your servings of vegetables at dinner 0 Eat two pieces of fruit with your lunch 0 Choose wholegrain bread 0 Have one or two beverages with or before each meal Delivering Nutrients and Eliminating Wastes The Cardiovascular System Delivery of digested and absorbed nutrients to the cells Capillaries small thinwalled blood vessels through which blood and the body s cells exchange gases and nutrients Lacteals lymph vessels in the villi ofthe small intestine that pick up particles containing the products of fat digestion 0 Part of the lymphatic system Heart and blood vessels the heart is the workhorse ofthe cardiovascular system 0 Veins blood vessels that transport blood and dissolved substances toward the heart Venules the smallest veins 0 Arteries blood vessels that transport blood and dissolved substances away from the heart Arterioles the smallest blood arteries Blood ow at rest 25 of blood goes to the digestive system 20 to skeletal muscles and the rest to the heart kidneys brain skin and other organs 0 Changes when eating or exercising Blood ow during exercise 70 directed to skeletal muscles during strenuous exercise Delivering Nutrients to the Liver Liver acts as a gatekeeper between the body and substances absorbed from the intestine 0 Some nutrients are stored in the liver some are changed into different forms and others are allowed to pass through unchanged Hepatic portal vein carries molecules from the intestine to the liver The liver determines whether nutrients are stored or delivered immediately to the cells The liver is important in the synthesis and breakdown of amino acids proteins and lipids The liver contains enzyme systems that protect the body from toxins absorbed in the GI tract Elimination of Wastes Gastrointestinal tract material not absorbed from the gut is eliminated as feces Lungs carbon dioxide and some water Skin water minerals and some nitrogen containing material Kidneys primary site for the excretion of metabolic wastes Overview of Metabolism Metabolism chemical reactions that break down molecules to provide energy and those that synthesize large molecules Mitochondria cell organs that responsible for breaking down molecules to release energy Cellular respiration occurs in the mitochondria The breakdown of glucose fatty acids and amino acids in the presence of oxygen to produce carbon dioxide and water and release energy Adenosine triphosphate ATP a highenergy molecule that the body uses to power activities NUTRITION 202 REVIEW EXAM 2 Proteins and Amino Acids 6 Compared to carbohydrates amp fats nitrogen is unique constituent of protein Proteins are made up of chains of amino acids linked by peptide bonds Unique side groups differentiate one amino acid from another Nonessential amino acids can be made in our bodies Essential amino acids must be in diet because body cannot make or make enough Conditionally essential amino acids may be needed in diet due to disease or unique metabolism Phenylketoneuria PKU individuals have an inherited metabolic disease that allows phenylalanine an essential amino acid to build up in blood causing brain damage they need to avoid aspartame amp nutrasweet in diet foods Condensation reaction builds up proteins from amino acid chains amp releases water Hydrolysis digestion reaction breaks down protein chain amp requires water Proteins have more different structures shapes and functions than carbohydrates and fats Peptide bonds connect amino acids to form proteins Disulfide bonds help give proteins their unique shapes amp functions Proteins have largest amp most complex shapes of all molecules which affect many functions Protein denaturation is uncoiling of shape amp loss of function due to heat acid alcohol metals ampor other agents Pepsin in stomach breaks some protein chains Proteases enzymes in small intestine hydrolyze or break down digest proteins into amino acids to be absorbed DNA is map or code for protein synthesis mRNA goes into nucleus picks up code for particular protein needed then back to cytoplasm tRNA picks up amino acids from cytoplasm amp carries them to mRNA for proper sequence assembly into protein on the ribosomes If an essential amino acid is missing protein synthesis stops or the body breaks down its own lean tissue to supply the necessary amino acid Sequencing errors alter function sickle cell anemia makes misshapen red blood cells that do not function properly Proteins have lots of valuable roles in body including structure and regulation Enzymes are proteins catalysts for reactions Hormones may be proteins blood carries hormone messengers to target tissues to switch on appropriate reaction Building blocks muscle amp collagen connective tissue Buffers acidbase regulators that help maintain pH homeostasis Carriers or transporters blood and cell walls Antibodies immune system components Water regulation water follows proteins with their multiple charges Others light sensitive pigments nerve transmission Energy amp glucose source but we should use them for more valuable roles Deamination for energy production nitrogen is removed creating ammonia which is toxic Liver filters out ammonia making urea less toxic and kidneys lter out urea for excretion in urine This may be detrimental to people with liver or kidney disease Protein Energy Malnutrition PEM major cause is poverty Marasmus protein and energy deficiency starvation affects primarily children growing fast they are very emaciated and apathetic Kwashiorkor recent protein deficiency yields fatty liver as enzyme synthesis stops amp food stacks up in liver these may look bloated in stomach area often affects recently weaned child in developing countries also susceptible to infections Health effects High protein often associated with high fat amp cholesterol heart disease Some amino acid supplements have been toxic tryptophan contamination Food allergies are an adverse immune response to a speci c protein in a food The most common food allergies are to peanuts tree nuts wheat soy milk eggs sh amp shellfish These must be on food labels since Jan1 2006 as they may cause death Food intolerances sensitivities may cause an unpleasant response but are not life threatening Celiac disease is autoimmune response to wheat protein and can cause malabsorption Monosodium Glutamate MSG Chinese Restaurant Syndrome may cause a collection of unpleasant symptoms Healthy adults should be in nitrogen balance every day Growing children pregnant women and people gaining weight are in positive nitrogen balance The sick and people losing weight are in negative nitrogen balance Protein recommendations are 1035 of calories Children amp growing or stressed bodies need more mature adults less Animal proteins are more complete higher quality than plant proteins which have limiting amino acids short in supply for complete body protein synthesis Complementary plant proteins mix amp mutually supplement to yield complete amino acid mix legumes cereals complete amino acid profile Reference protein digestibility and complete amino acid profile used to be egg protein but now Protein DigestibilityCorrected Amino Acid Score PDCAAS by FAOWHO is current standard based on needs of a growing child Humans do not store excess amino acids except as body tissues They are deaminated and used as energy or fat Protein is typically most expensive component ofthe diet Good sources of protein are meats poultry fish cereals beans nuts amp seeds Vegetarians use a good mix of plant proteins including beans amp cereals soy products nuts and may use eggs or dairy products Benefits of a vegetarian diet are lower body weight less chronic disease more economical diet Deficiencies of concern for vegetarians are Vitamin B12 iron zinc calcium Vitamin D Riboflavin Vitamin A and Omega 3 fatty acids Plenty of carbohydrate in diet spares protein for more valuable roles than energy production Muscle work builds muscles not protein supplements Most Americans and athletes get plenty of protein in normal diet and excessive protein is expensive and can be hard on the liver and kidneys Vitamins 7 Vitamin organic essential nutrients required in tiny amounts Bioavailavility rate and extent to which nutrient is absorbed amp used vitamins can be damaged by light oxygen heat and washing away Refrigeration slows deterioration as does cooking minimum time in minimum water Preparation method can be important Precursor substance that preceeds others some precursors can be converted to an active vitamin inside the body Fortification Adding nutrients to foods to prevent deficiencies or promote hea h Enrichment adding nutrients to restore those lost in processing Vitamin functions Coenzymes that increase activity of enzymes B vitamins are especially important in extracting energy in Krebs cycle Some vitamins are antioxidants that prevent cellular damage by preventing free radical formation Watersoluble vitamins are carried freely in watery blood and excesses are excreted by kidneys thus are not very toxic but excess can cause problems These are carried in the blood stream to the liver Vitamins come from a varied food supply especially fruits amp vegetables Toxicity is dose related response more is not always better fatsoluble vitamins and minerals can be toxic at high doses with no good excretion route Fat soluble vitamins are carried initially in chylomicrons in the lymph system till protein carriers are attached Water Soluble vitamins include 8 B Vitamins and Vitamin C B vitamins serve as coenzymes in energy metabolism TCA cycle and Electron Transport Chain so deficiencies lead to a lack of energy Thiamine coenzyme in energy release from nutrients nerves and muscle amp in synthesis of neurotransmitters for nerve cells De ciency disease is beriberi discovered with advent of rice polishing Also involved in WarnikeKorsakoff syndrome in alcoholics when alcohol decreases absorption of thiamine No reported toxicity Source pork whole grains legumes Leaches into cooking water Riboflavin coenzyme energy release from nutrients all body cells De ciency in ammation of membranes especially eyes and mouth Source milk whole grains green vegetables UV light destroys but not heat pasteurized milk is packaged in opaque cartons to protect ribo avin Niacin coenzyme in energy transfer lowers cholesterol functions in glucose and fatty acid metabolism Body can make it from tryptophan De ciency pellagra 4 D s diarrhea dermatitis dementia death was common in South till WW 1due to high corn diets deficient in niacin Toxicity niacin flush painful dilation of capillaries vomiting diarrhea UL 35 mgday Source meat poultry sh legumes grains other than corn Biotin coenzyme that carries 002 in TCA cycle De ciency rare can be induced by raw egg whites which have Avidin causes nausea hair loss lethargy Source egg yolks amp widespread in foods No reported toxicity Panothenic acid part of coenzyme A crossroads compound in metabolic pathways De ciency rare involves general failure all body systems Sources widespread in meats cereals vegetables Relatively nontoxic Vitamin B9 coenzyme in amino acid metabolism hemoglobin and DNA synthesis works with more than 100 enzyme systems De ciency depression amp confusion hastened by high protein diet making needs more Toxicity only with supplements causes neurological damage Source meat fish poultry vegetables and fruits Folate folic acid coenzyme transfers 1 C compounds in metabolism activates B12 assists DNA synthesis and cell growth prevents neural tube defects in babies Spina Bifida split or open spine Anencephaly fatal lack of brain Foods deliver it mostly in bound form B12 activates it 5 vegetables and fruitsday prevents de ciency FDA mandated fortifying grain products since many pregnancies are un planned but controversy resulted because it can mask B12 deficiency anemia but not cure B12 deficiency nerve damage De ciency megablastic anemia large immature red blood cell 02 de ciency Infants fed goats milk de cient in folate Associated with elevated homocysteine and heart disease risk Sources leafy green vegetables legumes oranges and fortified grains Vitamin Bg amino acid metabolism DNA synthesis Folate activation and nerve sheath maintenance Intrinsic factor in stomach is required for absorption Folate activates B12 De ciency usually due to poor absorption or lack of intrinsic factor atrophic gastritis is common after 60 amp B12 remains attached to food and is not absorbed Pernicious anemia large immature red blood cells muscle weakness and irreversible neurological damage Controversy Folate can cure blood symptoms but not nerve damage and can mask B12 deficiency Source animal products and forti ed grains Vitamin C ascorbic acid antioxidant and coenzyme works with enzyme to facilitate reactions ie Collagen connective tissue formation and strengthening as well as deactivating histamine and reducing congestion from a cold De ciency Scurvy requires 10 mgday to prevent it usually starts as bleeding gums and progresses to severe connective tissue break down and death results from hemorrhage Cooking destroys Vitamin C as well as exposure to iron or copper Toxicity quick withdrawal of megadoses causes scurvy symptoms due to over excretion Excess gives false results in some medical tests and cause nausea diarrhea amp cramps and erosion oftooth enamel UL is 2000mgday Sources citrus fruits and colorful vegetables Choline is a water soluble substance not currently considered a vitamin It is found in many foods and deficiency in U S is rare Excess above 35 gday can cause some symptoms like shy odor sweating low blood pressure amp reduced growth rate Supplements can provide nutritional insurance but can be expensive amp some can be toxic Vitamin A amp metallic minerals particularly Supplements though are regulated weakly by FDA They do not require proof of safety or efficacy before being marketed like food additives Many Americans have wellnourished toilets from excess water soluble vitamins Fat Soluble Vitamins A D E K Travel in lymphatic system require protein carriers Chylomicrons amp bile for absorption Stored in liver and fat tissues Not readily excreted so excess can be toxic De ciencies can take years to develop Vitamin A Precursor is carotene in plants Active in rhodopsin vision pigment preventing night blindness protein synthesis cell differentiation amp gene expression epithelial tissue maintenance growth of bones and teeth breaks down bone in preparation for elongation reproduction some antioxidant activity Retinol binding protein carrier used for transporting in blood amp requires zinc De ciency night blindness keratomalacia softening of cornea infectious disease measles can be deadly keratinization dry rough scaly skin very common in underdeveloped countries Toxicity affects all body systems teratogenic causes birth defects can consume toxic amounts from animal tissues liver amp supplements preformed Vitamin A only is toxic amp causes nausea vimitingdizziness headaches and can cause death Beta carotene excess from plants turns skin orange yellow but not toxic Source liver orange fruits and vegetables Vitamin D calcifero promotes calcium and phosphorous absorption and calcium mobilization from bone Body can make from cholesterol amp sunlight exposure liver and kidney are involved in activation sunshine vitamin Parathyroid hormone PTH stimulates activation of Vitamin D when blood calcium levels fall too low De ciency rickets soft bones in children osteomalacia poor bones amp teeth in young women osteoporosis thin brittle bones in elderly Toxicity calcium deposits and stones in soft tissues kidney stones and calcium deposits in arteries Sources fortified milk products amp sun on skin which converts cholesterol to Vitamin D Recommendations 515 micrograms UL 50 micrograms Iday Vitamin D may help prevent cancer amp other diseases Vitamin E tocophero Antioxidant especially for polyunsaturated fatty acids it inactivates damaging free radicals protecting cell membranes Antiinflammatory decreases LDL oxidation and platelet stickiness De ciency rare erythrocyte hemolysis or hemolytic anemia red blood cells break open usually only in premature infants Toxicity rare only in supplement megadoses interferes with Vitamin K amp blood clotting UL is 1000 mgday Sources Vegetable oils seeds and nuts Vitamin K blood clotting activation as well as bone formation Made by bacteria in intestine and also comes in foods De ciency hemorrhagic disease excessive bleeding may be caused by long term antibiotic use Newborn babies have sterile intestine given single dose Vitamin K at birth Toxicity not common only with supplements jaundice red blood cell hemolysis and brain damage Sources widespread in foods intestinal bacteria Antioxidants are compounds that prevent damage from free radicals that contribute to membrane and organ damage They include Vitamin A Vitamin E and Vitamin C Phytochemicals are plant materials pigments are most studied ones though there are others that have health benefits beyond normal nutrition One should eat a rainbow of fruits and vegetables every day Excess of fortified foods is expensive and may actually be dangerous due to toxicity issues Summary Foods are usually safe sources of nutrients Megadose supplements may not be safe especially fatsoluble vitamins Vitamin A definitely can be a problem Herbal supplements are available and relatively inexpensive but may interact with other nutrients and should be chosen with care Know the side effects and interactions FDA does not require supplements to prove safety or effectiveness and removes them from market only if many complaints are received Supplements are not regulated like Drugs or food additives which must prove safety and effectiveness Supplements should at least have a USP seal to ensure that they are manufactured well and contain the nutrients they have on the label Diet should emphasize Adequacy Variety Balance amp Moderation Water amp Minerals 8 Water is the most important nutrient Intracellular water within cells Interstitial fluid outside cells Water is about 60 of normal adult weight more muscle more water Hypothalamus in brain controls thirst Dry mouth is indicator of thirst Deficiency yields dehydration nausea weakness exhaustion even death Sources beverages foods metabolic breakdown of energy nutrients Losses kidney skin lungs feces Dietary Recommendations 2 3 quartsday or more for active people Homostasis of water is maintained by kidney Fluids in body are electrolyte solutions with or charges Sodium and chloride primarily outside cells interstitial fluids Potassium primarily inside cells intracellular fluids Osmosis moves water to most concentrated solute side of a membrane amp regulates water balance within body compartments Blood pressure also moves water in body Proteins may act as pumps or carriers Fruits and vegetables are best food sources of water Acid base balance in body fluids should be stable homeostasis Water intake is regulated by thirst hypothalamus Water loss is regulated by kidneys which filter blood Antidiuretic hormone ADH signal kidneys to reabsorb water concentrating urine Sodium and dissolved minerals affect this Water Functions Transports nutrients amp waste maintains structure of large molecules especially proteins and carbohydrates universal biological solvent lubricant regulates temperature maintains blood volume Well hydrated pale yellow urine Dehydration dark colored urine Must replace sweat when working or exercising Untreated dehydration is a medical emergency Infants the elderly and athletes are at high risk of dehydration 10 of weight lost can lead to death Hyponatremia water intoxication occurs with too much water relative to sodium in blood Environmental Protection Agency EPA regulates municipal water supplies Food amp Drug Agency FDA inspects bottled water suppliers Bottled water is not usually better than tap water but may be more convenient and is more expensive Minerals are inorganic elements they are not digested but do regulate many body processes Major minerals are required in larger amounts Minor trace minerals are just as necessary but are required in smaller amounts Food content depends on soil amp water composition while food is growing Bioavailability varies depending on many factors food meal and personal factors phytates oxylates tannins and fiber may tie up minerals and flush them through bodies Minerals are active in many body systems especially as cofactors in enzyme systems Safe intake range is often narrow supplements food may be too much Interactions are common excess of one may cause deficiency of another some use the same carrier Mineral functions body structure water balance energy production gene expression cofactors in enzyme systems interact with other nutrients and components of diet Major Minerals Electrolytes Sodium Potassium and Chloride maintain water balance and nerve transmission Electrolyte deficiency problems with acidbase balance muscle cramps confusion apathy constipation heart beat amp even death Electrolyte toxicity potassium can cause heart to stop sodium can cause high blood pressure in some individuals Sodium is the major cation in extracellular fluid controlled by kidney De ciency Hyponatremia muscle cramps not common but may occur with rapid influx of water Toxicity edema swelling or Hypertension high blood pressure which may or may not respond to salt restriction Hypertension high blood pressure is a major killer in US damages arteries kidney and heart May be controlled by exercise and proper diet or by drug therapy To control hypertension increase activity reduce weight to normal and use the DASH diet Focuses on more plant foods especially 910 fruits and vegetablesday and choose lean meats and dairy If necessary take medication regularly to control high blood pressure Sources of Sodium Salts or processed amp animal foods have a lot of sodium high in most US diets Chloride major anion in extracellular fluid maintaining fluid balance and pH of body uids and source for Hydrochloric Acid in stomach for digestion of foods De ciency rare Toxicity Vomiting Sources Salt meats milk processed foods Potassium major cation inside cells most common electrolyte deficiency May prevent or correct hypertension when balanced well with Sodium Important in nerve impulse and muscle contraction Aids bone strength De ciency muscle weakness amp confusion Toxicity weakness amp vomiting Used in lethal injections Sources bananas fresh fruits vegetables amp legumes low in most US diets Bone Health collagen protein calcium phosphorous magnesium sodium amp fluoride in proper concentrations Bone is constantly being broken down and built up Peak bone mass is built about age 30 After about 45 bone mass decreasesleading to bone fragility and osteoporosis in some elderly Osteoporosis risk depends on gender age race family history body size smoking exercise alcohol intake and diet The switch from milk to cola drinks messes with calciumphosphorous ratios amp leads to more osteoporosis Calcium most abundant mineral in body 99 in bones and teeth provides rigidity Hydroxyappetite crystals of calcium and phosphorous in bones and teeth makes them rigid 1 Calcium in blood is critical muscle contraction nerve transmission blood clotting body will maintain it at expense of bone density through actions of parathyroid hormone which increases Ca and calcitonin which decreases Ca in blood May also ght cancer reduce kidney stone risk reduce obesity risk Blood concentration is always maintained bones and teeth suffer with Deficiency yields osteoporosis in later years or rickets in children amp osteopenia in young people Toxicity stones in soft tissues like kidneys and arteries nausea vomiting constipation and may interfere with zinc iron magnesium amp phosphorous Sources milk sh greens amp legumes Calcium absorption is affected by oxylates phytates tannins ber and food source Phosporous 85 in bones and teeth rest in DNA phospholipids membranes amp ATP high energy phosphate bonds which yield energy when broken De ciency rare in U S causing weakness amp bone pain rickets amp may be caused by overuse of aluminum containing antiacids Toxicity low blood amp bone calcium and can lead to calci cation of soft tissues UL 4000 mgday Sources animal foods amp soft drinks Magnesium over half in bones lots ofenzymes ATP catalyst Mild to moderate deficiency is common in US De ciency severe weakness amp confusion is rare but can result from use of diuretics and some antibiotic use Toxicity none from foods but some from supplements diarrhea amp dehydration UL is 350mgday Sources nuts legumes grains amp fish Sulfur is mostly in protein disulfide bridges which shape protein molecules giving them functionality De ciency Unknown in US Toxicity from supplements only but fairly rare in US Sources protein foods and some food preservatives Trace Minerals M is required in small amount deficiency or toxicity can be fatal Bioavailability depends on many factors interactions are common Balance is critical toxicity generally only with supplements Iron is most common deficiency in U S and world anemia amp apathy Most is found in hemoglobin blood carries 02 Some in myoglobin muscle handles 02 MFP factor meat fish poultry enhances absorption of iron Heme Iron from animals is well absorbed Nonheme iron from plants is not as well absorbed Iron in is carried in blood by transferring Iron is lost primarily through blood loss Women need more than men Women children and elderly most vulnerable to deficiency Pica appetite for nonfood substances often associated with deficiency Men may have excess associated with heart attack Hemochromotosis genetic enhances absorption amp deposits pigments in tissues damaging them Iron overdose from vitaminmineral supplements is leading cause of accidental poisoning in children De ciency anemia weakness apathy most common nutrient de ciency in world Toxicity infection liver injury growth failure heart problems most common form of poisoning for children under 6 in US Sources Red meats sh eggs legumes dried fruits enriched grains Copper involved in collagen manufacture amp wound healing De ciency rare anemia Toxicity vomiting diarrhea amp liver damage Can be genetic Menke s cells absorb but can t release it Wilson s accumulates in liver and brain UL is 10mgday Sources sea foods nuts whole grains legumes m Gene expression many enzyme systems immune functions sexual maturity Better absorbed from animal foods In blood also requires transferrin carrier thus competes with iron amp copper De ciency in children retards growth sexual maturity amp impairs wound hea ng Toxicity vomiting diarrhea headache exhaustion suppressed immune system UL 40 mgday Sources protein foods throat lozenges amp galvanized metals Selenium antioxidant prevents free radical formation and reactions with many enzymes part of glutathione peroxidase that protects cells from oxidative damage may help prevent cancer De ciency heart disease inland China Keshan Disease Toxicity selenosis epithelial skin nail amp hair amp nerve disorders UL is 40 microgramsday Sources seafood meats whole grains dairy amount depends on soil Iodine needed for thyroid hormone thermostat regulating metabolism De ciency goiter enlarged thyroid or creatinism physical and mental retardation in child if woman is pregnant Toxicity also enlarges thyroid Goitrogens antithyroid compounds in cabbage family Primary sources Seafood or iodized salt inland areas UL is 1100 microgramsday Chromium enhances activity of insulin De ciency yields diabetes type condition Toxicity rare Sources Meats unrefined foods yeast fats Chromium picolate is a popular athletic supplement thought to reduce body fat and increase muscle mass Fluoride strengthens crystal deposits in bones and teeth prevents cavities caries De ciency tooth decay Toxicity excess can stain teeth during formation fluorosis or cause nerve damage amp even death Sources Tooth Paste Well water or many cities uoridate water Bottled water does not contain uoride UL is 10mgday Manganese bones liver kidney amp pancreas cofactor for enzymes De ciency is rare Toxicity is usually from environmental contamination Sources nuts whole grains leafy vegetables Molybdenum cofactor for several metalloenzymes De ciency rare Toxicity rare Sources legumes cereals organ meats Heavy metals displace proper minerals lead and mercury are very toxic especially for growing child Sources Environmental contamination old paints newsprint pencils Energy Balance and Weight Management 9 Healthy weight does not increase risk ofdisease Lean body mass includes bone muscle internal organs also called fat free mass Overweight is 1015 pounds too much 65 of Americans BMI gt 25 Obese is 2540 or more pounds too much 32 of Americans BMI gt30 Overweight increases risk of hypertension stroke heart disease gallbladder disease diabetes arthritis cancer sleep apnea and chronic disease thus increasing health care costs Underweight BMI lt 185 depresses immunity does not allow energy for exercise and does not provide reserves for medical emergencies Body Mass Index BMI weight related to height is used because it is inexpensive noninvasive and easy to measure Body composition tells more about health fat vs muscle mass than BMI but is harder amp more expensive to measure Men should be 1020 fat Women should be 2132 fat Techniques to measure body composition Calipers measure subcutaneous fat only Bioelectric Impedance is becoming inexpensive passes current through muscle Dual Energy X Ray Absorptometry DEXA is expensive but very accurate Underwater Weighing vs air weighing is considered the gold standard but is expensive time consuming and hard to do accurately BodPod Air Displacement is newest but also expensive equipment Visceral fat around abdomen is worse than subcutaneous fat under skin Apple shape is worse than pear shape Energy balance Weight maintenance depends on food intake and energy expenditure Americans are eating more with portion distortion amp moving less Positive energy balance leads to weight gain Negative energy balance leads to weight loss Components of Energy Needs Basal Metabolic Rate BMR 6070 just keeps alive Physical Activity 1530 Exercise or work NonExercise Activity Thermogenesis NEAT everything other than sleeping eating amp sports Thermic Effect of Food TEF10 needed to digest absorb and process food size and composition of meal affects this Factors that affect Basal Metabolic Rate Body composition higher lean body mass Body build ta andor thin looses more heat Age younger is usually more active Gender men have more muscle Genes family history Ethnic effect African American less than Caucasian Hormones Thyroid regulates BMR Starvation multiple dieting can reduce BMR Environmental temperature cold raises BMR Caffeine raises BMR Drugs may increase BMR Exercise Sedentary people spend a lot less than active people over prolonged time Effects of too few calories Stored glycogen and fat are depleted Body proteins break down to fuel brain Ketone bodies are generated from incomplete breakdown of fats as glucose is depleted Death often occurs with depletion of 13 of lean muscle mass Effects of too many calories Excess calories stored as fat regardless of source Fat cells have unlimited capacity to store fat Chronic disease may develop Adipocytes fat storage cells can get larger than other body cells and can increase in number Will shrink with food shortage but grow again easly with food excess Estimated Energy Requirement EER calories needed to maintain weight Factors that affect weight Genes Environment Appetite psychological desire for food Hunger physiological need for food Satiety determines time between eating occasions Hormones Leptin affects hunger amp activity Ghrelin increases hunger when stomach is empty Cholecystokinin decreases hunger when stomach is distended Insulin decreases hunger Glucogon increases hunger Many override feedback mechanisms resulting in energy imbalance Environmental factors may increase hunger and decrease activity Toxic food environment lots of delicious and very convenient relatively cheap high calorie foods along with less time and motivation to exercise Set Point Theory says the body wants homeostasis constant conditions and resists changes in weight Thrifty genes during starvation periods overweight people would live and reproduce thus some populations may have more ofthese What is a reasonable rate of weight loss 2 to 2 pounds per week Weight gain success for underweight Add extra 500 calday for 1 pound of weight gainweek Choose more energy dense food juice or milk instead ofwater Eat more frequent energy dense snacks muffin instead of bread nuts dried fruits Strength train to gain muscle ratherthan fat Fad diets promise dramatic results but deliver poor results Fast weight loss 2 muscle and 2 fat Slower weight loss A muscle and fat Success with weight loss Focus on nutrient dense foods not energy dense foods ie fruits and vegetables Get enough volume for satiety Use My Pyramid Guidelines Replace sodas with water Increase exercise Break bad habits Make permanent rather than temporary changes to avoid regaining weight Weight cycling Yoyo dieting can be worse for health than mild overweight and can decrease BMR with each cycle unless increased exercise is used to increase BMR Extreme weight loss measures Very low calorie diets controlled starvation need medical supervision Liposuction results are not permanent unless habits are changed can cause infections scars swelling and excessive bleeding Gastric Surgery dramatic weight loss is possible but does cause mal absorption ulcers gallstones bleeding and require constant medical monitoring Weight can be regained if habits are not changed permanently America needs multiple behavior food exercise and community changes to better manage weight and health issues Prescription Medications have side effects are expensive and must be taken for life Sibutramine Meridia appetite suppressant Phentermine Adipex appetite supressant Orlistat Xenical fat blocker gas bloating diarrhea Over the counter drugs Alli fat blocker has side effects like Orlistat Ephedra was banned in US in 2004 after multiple users died of heart attacks and strokes but some herbals still contain it Extreme weight loss measures Very low calorie diets controlled starvation need medical supervision Liposuction results are not permanent unless habits are changed can cause infections scars swelling and excessive bleeding Gastric Surgery dramatic weight loss is possible but does cause mal absorption ulcers gallstones bleeding and require constant lifelong medical monitoring Eating Disorders affect millions more women than men Psychological and physiological problem where individual suffers experience a distorted view oftheir bodies and have an intense fear of being fat Multiple factors contribute including genetic low self esteem need for control and unrealistic media factors Anorexia Nervosa self starvation causing electrolyte imbalance low blood pressure decreased heart rate osteoporosis and very thin bodies It may result in death In women may lead to amenorrhea absence of menstruation Relapse is frequently common and can be deadly Bulimia Nervosa individuals look fairly normal but binge and purge inappropriately They may eat 10000 calories at a sitting then vomit or exercise obsessively to get rid of excess calories Vomiting cause tooth decay gum disease broken blood vessels electrolyte imbalance Not as fatal as Anorexia but still difficult to treat Binge Eating Disorder Individuals overeat but don t purge so many are ovenNeight Warning signs of Eating Disorders Low or high body weight Preoccupation with food fat and calories Distorted body image Loss of menstrual period Changes in mood Hair loss Avoids eating with others Treatment is multidisciplinary recovery is slow and there is greater success if treated early in process Relapse is common


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