Nutr 303 Exam 3 Study Guide
Nutr 303 Exam 3 Study Guide NUTR 303
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11102014 Nutrition 303 Exam 3 Study Guide Chapter 10 Antioxidant Nutrients Free Radicals Free Radical An unstable atom with an unpaired electron in its outermost shell Reduction The process of gaining an electron during a Chemical reaction Oxidation The process of loosing an electron during a Chemical reaction Normally bonds between atoms or molecules are strong sharing electrons in the outer shell makes the bond strong I Oxidation of these bonds usually produces stable compounds However sometimes bonds between atoms or molecules may be weak I When these bonds split a molecule or atom may be left with an unpaired electron in the outer shell The presence of the free electron results in a situation in which the number of positive Charges contribute by the nucleus of the atom is no longer equal to the number of negative Charges in the electrons surrounding the nucleus Free radicals are Chemically reactive and sometimes aggressive To reestablish a balance between positive and negative Charges the free radical pilfers an electron from an adjacent stable atom or molecule I once this process starts it s a Chain reaction I with the loss of an electron that nearby molecule now becomes an unstable free radical I In order to reestablish neutrality it looks to acquire an electron from another adjacent molecule The body s natural defense and repair systems try to control the destruction by free radicals but these systems are not 100 effective Overproduction of free radicals can be deleterious to our healthy cells I Damage can happen at two levels cell membrane or inside the cell disrupting cell function and growth 0 Remember cell membrane is a lipid bilayer Phospholipids primarily compose these layers Overproduction The hydrophilic attracted to water heads of phospholipid molecules are aligned to the inside cytoplasm or outside extracellular uid of the cell The tails which are fatty acids are hydrophobic or lipophiliC attracted to fat and are aligned toward each other in the interior of the cell membrane I when free radicals pilfer electrons from the heads of the phospholipids the cell membrane loses its integrity The chain of the lipid is broken and so is the cell s ability to regulate the ow of water and nutrients in and out of it Eventually with enough breakage the cell will collapse Specific structures and molecules within the cells can be damages by free radical overproduction O Damage to LDL proteins low density lipoproteins can contribute to plaque formation and atherosclerosis O Alteration of DNA as in the case of some skin cancer results in altered protein synthesis 0 The Chemical damage produced by free radicals has been linked to cancer atherosclerosis arthritis diabetes emphysema kidney disease Alzheimer s Parkinson s cataracts Excessive sunlight water and air pollution radiation asbestos ozone and toxic chemicals has been shown to accelerate the formation of free radicals Anti0xidant protects the cell from free radical damage Antioxidant substance that has the ability to prevent or repair the damage cause by oxidation Vitamin Compound needed in small amounts to help regulate and support chemical reactions and processes in the body Phytochemical A chemical found in plants Some may contribute to a reduced risk of cancer or cardiovascular disease in people who consume them regularly The body has two principal defense mechanisms to limit or defend against the adverse effects of free radicals enzyme systems and antioxidant chemicals Antioxidant chemicals are derived from food 0 They include vitamins a vitamin precursor and phytochemicals These Antioxidants principally function by donating an election or hydrogen atom to reactive molecules to stabilize the molecule s structure I they then become unstable but because of their unique structure they are not reactive molecules prone to induce cellular damage I the enzyme systems and dietary antioxidants work in concert to limit free radical formation destroy free radicals and assist in repairing oxidative damage induced by reactive molecules Since electron pairing is desired for optimal stability free radicals steal electrons from other molecules Antioxidants usually can donate an electron without stealing from another molecule Respiration converting fuels to energy results in reduction of oxygen by four electron Incompletereduction leads to partially reducedspecies which are either free radicals themselves or precursors to free radicals Collectively these are known as reactive oxvgen species ROS Examples Hydrogen peroxide 0 Superoxide 0 Hydroxyl radical Vitamin E 0 Vitamin E is a family of four tocopherols and four tocotrienols called alpha beta gamma and delta They differ in that tocopherols have a saturated side chain whereas the tocotrienols have a unsaturated side chain 0 Alpha tocopherol is the most biologically active and the most potent 0 Vitamin E is unique in that many animal species it has an essential function in fertility where it does not appear to have this function in humans 0 Vitamin E is important for the formation of muscles and the central nervous system in early human development 0 The principal function of vitamin E in humans is as an antioxidant Vitamin E is a fat soluble vitamin found primarily in adipose tissue and in the lipid bilayers of cell membranes 0 Many of the lipids within these membranes are polyunsaturated fatty acids PUFA The unsaturated double bond is not as stable as a saturated single bond in saturated fatty acids PUFAs are particularly susceptible to oxidative attack by free radicals O The formation of free radicals may destabilize the cell membrane which may ultimately alter the ability of the cell to function properly Vitamin E can donate electrons or hydrogen to free radicals found in membranes thereby making them more stable 0 The antioxidant function of vitamin E appears to be critical in cells continually exposed to high levels of oxygen particularly red blood cells and the cells lining the lungs 0 Increasing vitamin E intake has also been suggested as a way to prevent several chronic disease that are linked to oxidative damage 0 For example oxidize LDL cholesterol is a major component of the plaque that develops in arteries which leads to atherosclerosis 0 Vitamin E is thought to attenuate the development of atherogenic plaque due to its ability to prevent or reduce the formation of oxidized LDL cholesterol 0 Oxidative damage to proteins in the eye leads to the development of cataracts 0 Vitamin E has been shown to improve vitamin A absorption if the dietary intake of vitamin A is low 0 Vitamin E also function in the metabolism of iron within cells and it helps maintain nervous tissue and immune function 0 Vitamin E is only synthesized by plants plant produces especially the oils are the best sources 0 Vitamin E is susceptible to destruction by oxygen metals light and especially repeated use in deep fat frying thus the vitamin E content of a food depends on how it is harvested processed stored and cooked 0 The RDA of vitamin E for adults is 15 milligrams per day of alpha tocopherol the most active natural form of Vitamin E d isomer This amount equals 224 milligrams of the less active synthetic source dl isomer 0 Daily Value used on food and supplement labels is 30 milligrams Preterm infants tend to have low vitamin E stores because this vitamin is transferred from mother to baby during the late stages of pregnancy 0 The potential for oxidative damage which could cause cell membranes of red blood cells to break hemolysis is of particular concern for preterm infants The rapid growth of preterm infants coupled with the high oxygen needs of their immature lungs greatly increases the stress on red blood cells 0 Special vitamin E fortified formulas and supplements designed for preterm infants compensate for lack of vitamin E 0 Unlined other fat soluble vitamins vitamin E is not stored in the liver It is stored in adipose tissue throughout the body 0 The Upper Level for vitamin E is 1000 milligrams per day of supplemental alpha tocopherol 0 Excessive intake of vitamin E can interfere with vitamin K s role in clotting mechanism leading hemorrhage O The risk of insufficient blood blotting is especially high if vitamin E is taking in conjunction with anticoagulant medication 0 Deficiency O Decreased Growth Reproductive failure name tocopherols means to bring forth birth Breakdown of cell membranes Hemolysis RBC break open 0 O O O Nerve degeneration Vitamin C Vitamin C known as ascorbic acid or ascorbate has a specific function in the synthesis of numerous compounds in the body including collagen carnitive and two neurotransmitter serotonin and norepinephrine Synthesized by most animals not humans and decreased absorption with high intakes Vitamin C is required for the synthesis of carnitine a compound that transports fatty acids into the mitochondria The best understood function of vitamin C is its role in the synthesis of collagen o This protein is highly concentrated in connective tissue bone teeth tendons and blood vessels The important function of vitamin C in the formation of connective tissue is exemplified in the early symptoms of a deficiency pinpoint hemorrhages under skin bleeding in gums joint pain Vitamin C is very important for would healing it increases the cross connection between amino acids found in collagen greatly strengthening the structural tissues it helps form 0 Without adequate vitamin C wounds will not heal Vitamin C also has a more general function acting as antioxidant because it can readily accept and denote electrons These antioxidant properties have been postulated to reduce the formation of cancer causing nitrosamines in the stomach Vitamin C aids in the reactivation of Vitamin E after is has donated an electron to a free radical Some studies think Vitamin C may be effective in preventing of cancers esophagus mouth and stomach and cataracts Vitamin C enhances iron absorption by keeping iron in its most absorbable form especially as the mineral travels through the alkaline environment of the small intestine O Consuming 75 milligrams or more Vitamin C at a meal significantly increases absorption of the iron consumed at that meal 0 Vitamin C is vital for the function of the immune system especially for the activity of certain cells leukocytes in the immune system Thus diseases and infections can increase the need for vitamin C 0 Upper Level of vitamin C is 2000 milligrams Note when vitamin C is consumed in large doses the amount in excess of daily needs mostly ends up in the feces or urine 0 The kidney start rapidly excreting vitamin C when intakes exceed 100 milligrams a day Recommended intake level for Vitamin C smokers and nonsmokers 0 The adult RDA of vitamin C is 75 milligrams for women and 90 milligrams for men per day 0 Daily Value used on food and supplement labels is 60 milligrams 0 Tobacco users need to add an extra 35 milligrams per day to the RDA O The toxic byproducts of cigarette smoke and the oxidizing agents found in tobacco products increase the need for the antioxidant action of vitamin C Foods Rich in Vitamin E amp C and impact of cooking 0 Foods high in Vitamin E I Wheat grains some fortified breakfast cereals cabbage asparagus avocados sweet potatoes tomato apples mangos nuts seeds shrimp peanut butter 0 Vitamin E is susceptible to destruction by oxygen metals light and especially repeated use in deep fat frying thus the vitamin E content of a food depends on how it is harvested processed stored and cooked 0 Vitamin C major sources are citrus fruits strawberries green peppers cauli ower broccoli cabbage papayas and romaine lettuce O The brighter the fruit or vegetable the higher it tends to be in vitamin C 0 Vitamin C is rapidly lost in processing and cooking as it is unstable in the presence of heat iron copper or oxygen and is water soluble 0 When fruits and vegetables are boiled for an extended time much of the vitamin is destroyed or leached out of the food and found in the discarded water Carotenoids relating to Vitamin A and rich food sources 0 Plants contain pigments called carotenoids They are phytochemicals that is chemicals within plants that have health promoting properties for humans 0 A provitamin precursor to Vitamin A partially converted to vitamin A retinol in the body 0 Carotenoids act as antioxidants by scavenging radicals not reused 0 Carotenoids can be turned into Vitamin A they are termed provitamin A 0 Only three of the more than 600 identified carotenoids are currently known to serve as provitamin A in humans O Beta Carotene the orange yellow pigment in carrots is the most potent form of provitamin A O The other two carotenoids that can be converted into vitamin A though not every efficiently are alpha carotene and beta cryptoxanthin The provitamin carotenoids are mainly found in dark green and yellow orange vegetables and some fruit Carrots spinach and other greens winter squash sweet potatoes broccoli mangos cantaloupe peach and apricots Carotenoids acts as antioxidants and have been shown to have beneficial effects in the prevention of oxidative damage and subsequent development of macular degeneration cardiovascular disease and cancer Performed Vitamin A retinyl palmitate 0 Animal Source foods 0 Highest concentrations liver turkey giblets O Fortified foods milk almond beverage Biological function for selenium and the antioxidant it works with Selenium is a trace mineral that exists in many readily absorbed chemical forms Selenium s best understood role is aiding the activity of one of the body s natural antioxidant enzymes glutathione peroxidase Seleno cysteine is co transnationally made and incorporated into proteins mammals amp bacteria Glutathione peroxidase chemically converts potentially damaging peroxides hydrogen peroxide for example into water In the functioning as a part of out natural antioxidant enzyme system selenium spares vitamin E and indirectly helps maintain cell membrane integrity Selenium also functions by activating thyroid hormone and in immune function Low blood levels of selenium have been liked with an increased incidence of some forms of cancer specifically prostate cancer Selenium deficiency symptoms in humans include muscle pain and wasting and a certain form of heart damage Functions of selenium O Antioxidant part of the enzyme glutathione peroxidase work together with vitamin E 0 Production of thyroxin thyroid hormone 0 MAY decrease the risk of cancer Diseases in which oxidative stress is implicated as a contributing factor 0 Chronic diseases take a long time to develop Cancer heart disease hypertension diabetes complications 0 Degenerative diseases associated with aging and breakdown of tissues Eye diseases cataracts macular degeneration AREDS 2 Alzheimer s disease Parkinson s disease 0 Alcoholic liver disease Chapter 11 Bone Structures and the role of osteoblasts and osteoclasts in bone remodeling 0 Think of the bone having three major components each with a specific function 1 Periosteum 2 Bone cortical and trabecular 3 Bone Marrow 0 Periosteum is the thick fibrous vascular membrane that covers most of the cortical bone surface 0 Muscles tendons and ligaments connect to it 0 The periosteum does not cover the ends of long bones as you need cartilage there for joint articulation 0 Cortical bone is sometimes called dense or compact bone 0 Comprises 80 of adult bone mass 0 The outer portion of nearly all bones is composed of dense strong cortical bone 0 The principal function of cortical bone is to provide strength and stability 0 Microscopic opening in cortical bone allow blood vessels and nerves to pass through providing nutrients and hormones to bone cells 0 Where cortical bone provides strength and stability trabecular bone provides more 0 O O O 0 Provides structural stability but because it is not so rigid it acts more like a shock absorber Lightens bones Lattice like matric of trabecular bone has small cavities that can be filled with marrow or connective tissue Trabecular bone is predominant in the ends of long bones vertebrae rib cage and at bones of the pelvis 20 of adult bones miss is trabecular 0 Bone marrow O O O Marrow is a spongy tissue that contains stem cells There are two types I Hemopoietic capable of developing into blood I Stromal cells that can produce fat cartilage and bone Infancy bone marrow is red due to high number of blood producing cells With age more and more marrow becomes yellow re ecting a higher number of fat cells I in adulthood on about 50 is red Bone marrow is primarily located in at bones hip breast rib shoulder blade and vertebrae and in the shafts of long bones The head of the demur ball joint at hip and humerus forearm at elbow Marrow is located in pockets of trabecular bone 0 Osteoblast Bone cells that initiate the synthesis of new bone 0 Osteoclast Bone cells that break down bone and subsequently release bone minerals into the blood 0 The growth maintenance and repair of bones involve a compleX relationship between the synthesis of new bone by the osteoblast and the breakdown of bone by osteoclast 0 Osteoclasts produced from stem cell bone marrow bring out resorption the process of losing substance Bone resorption is part of the initial process for remodeling and growth that is they break down or degrade small amounts of bone 0 O In doing so minerals embedded in bone matriX including calcium phosphorus and magnesium and freed and released into the blood The resynthesize of new bone is then accomplished by the activity of osteoblasts from bone marrow These osteoblast embed within the dissolved resorption bay provide by the osteoclasts The osteoblasts take up free calcium and phosphorus and along with collagen form a compleX mixture called hydroxyapatite This mixture adds strength and structure to the bone Some osteoblasts become embedded within the bone matriX and become osteocytes Synthesis of bone for repair or growth is a function of the osteoblast Remodel and Bone growth 0 Osteoblasts make new bone 0 Osteoclasts resorb bone 0 Osteocvte bone cell Biological and Lifestyle Factors that in uence bone health TABLE 101 Biological Factors Associated with Bone Status Biological Factors Effect on Bone Status Sex Women have lower bone mass and density than men Age Bone loss occurs atter age 40 Ethnicity Caucasian or Asian heritage are at greater riskier poor bone health than individuals of Airican descent Frame size People with small bones have a lower bone mass TABLE 102 Modifiable Lifestyle Factors Associated with Bone Status Lifestyle Factors Adequate diet containing an appropriate amount of nutrients l lealthy body weight Normal menses Weight bearing physical activity Smoking Medications Excessive intake of protein phosphorus sodium caffeine wheat bran alcohol inadequate UV B exposu re Call to Action 9 Follow Mvaramid with special emphasis on adequate amounts of fruits vegetables and low fat and fatsfree dairy products I Consider use of fortified foods or supplements to make up for specific nutrient shortfalls such as vitamin D and calcium 9 Maintain a healthy body weight iBiVll of l85 24 l to support bone health 0 During childbearing years seek medical advice if menses cease such as in cases of anorexia nervosa or extreme athletic training in Women at menopause and beyond should consider use of cur rent medical therapies to reduce bone loss linked to the fall in estrogen output II Perform weight bearing activity as this contributes to bone maintenance whereas bed rest and a sedentary lifester lead to bone loss Strength training especially upper body is help ful to bone maintenance Smoking lowers estrogen synthesis in women Cessation is advised Passive exposure is a risk 0 Some medications thyroid hormone cortisol diuretics stimui late urinary calcium excretion 39 Some medications alcohol diuretics cancer meds stimulate urinary excretion of magnesium 0 Moderate intake of these dietary constituents is recommended Problems primarily arise when excessive intakes of these nutrin ents are combined with inadequate calcium consumption 1quot Excessive soft drink consumption is especially discouraged Iquot If sunlight exposure is limited r i045 minutes per day with out sunscreen due to time or environmental conditions focus on food or supplements to meet current Al for vitamin D Describe the synthesis activation sites of action for maintain bone health and food sources of vitamin D Humans synthesize Vitamin D from cholesterol like substance by the action of sunlight on their skin Vitamin D is later acted on by the liver and kidneys to form the hormone calcitirol This hormone increases calcium absorption in the intestine and works with another hormone PTH to maintain blood calcium levels within a narrow range Rich food sources of Vitamin D are fish oils and fortified milk Regulates blood calcium 0 Along with the parathyroid hormone O Regulates calcium phosphorus absorption 0 Reduces kidney excretion of calcium 0 Regulates calcium deposition in bones Good Sources of Calcium and factors influencing absorption Calcium is the most abundant major mineral in the body Functions of calcium 0 Form and maintain bones and teeth 0 Transmission of nerve impulses 0 Aiist in muscle contraction Calcium absorption is 0 Is inhibited by oxalate phvtates and some fibers 0 Magnesium competes with Ca2 for intestinal absorption higher Mg will impede Ca absorption 0 Optimal vitamin D status promotes calcium absorption 0 Calcium absorption increases when status is low 0 Absorption of Ca is typically 254 but can rise to M 0 Reguires adequate vitamin D Osteoporosis and three factors I Osteoporosis the presence of a stress induced fracture or a T score of 25 or lower The bones are porous and fragile due to low mineral density 0 Osteoporosis 1 Porous trabecular bone characterized by rapid bone demineralization following menopause I Osteoporosis 2 Porous trabecular and cortical bone observed in mean and women after the age of 60 0 Risk Factors 0 Age is a factor for osteoporosis because I Bone mass decreases with age I Age related hormonal changes in uence bone density I Older adults are less able to absorb vitamin D 0 Gender is a risk factor for osteoporosis I 80 of Americans with osteoporosis are women I Women have lower bone density than men I Estrogen loss in post menopausal women causes increased bone loss 0 Physical activity in uences the risk for osteoporosis I Regular exercise causes stress to bones leading to increased bone mass I Weight bearing activities walking jogging are especially helpful in increasing bone mass 0 Progression of osteoporosis may be slow down by I Adeguate calcium and vitamin D intake I Regular exercise I Anti resorptive medications Chapter 7 Energy Balance and Weight Control Define Energy Balance an impact the imbalance on body weight 0 Energy Balance the state in which energy intake in the form of food and beverages matches the energy expended primarily through basal metabolism and physical activity 0 Energy Input calories from food intake Energy output metabolism digestion absorption and transport of nutrients physical activity 0 When energy input is greater than energy output the result is positive energy balance The excess calories consumed are stored which results in weight gain 0 If energy input is less than energy output there is a calorie deficit and negative energy balance results A negative energy balance is necessary for successful weight loss 0 Important to realize that during negative energy balance weight loss involves a reduction in both lean and adipose tissue not just fat Energy Expenditure and the relative contribution of each to the total energy expenditure 0 Energy Expenditure energy expended at rest and during physical activity 0 The body uses energy for three general purposes basal metabolism physical activity and digestion absorption and processing of ingested nutrients 0 Basal Metabolism the minimal amount of calories the body uses to support itself in a fasting state when resting and awake in a warm quiet environment It amounts to roughly 1 kcal per kilogram per hour for mean and 9 kcal per kilogram per hour for women these values are often referred to as basal metabolic rate BMR 0 Accounts for about 60 to 70 of total energy use by the body 0 Includes beating of the heart respiration by the lungs and the activity of other organs such as the liver brain and kidney 0 If the person is not fasting or completely rested the term resting metabolism is used and expressed as resting metabolic rate RMR An individual s RMR is typically 6 higher than her BMR 0 Physical Activity Physical activity increases energy expenditure above and beyond basal energy needs by as much as 25 to 40 o TEE BMR TEF O Thermic Effect of Food The increase in metabolism that occurs during the digestion absorption and metabolism of energy yielding nutrients This represents 5 to 10 of calories consumed 0 Increase with protion consumed O 5 to 10 of TEE Relationship between fat free mass and total energy expenditure 0 Lean body mass body weight minus fat storage weight equals lean body mass This includes organs such as th brain muscles and liver as well as bone and blood and other bodily uids 0 Fat free mass is main determinant of Total Energy Expenditure Factors that raise and lower BMR 0 Factors that increase BMR 0 Greater lean body mass Larger body surface per body volume Male Gender greater lean body mass Body temperature fever or cold environmental conditions Thyroid hormones Aspects of nervous system activity release of norepinephrine OOOOO 0 Pregnancy 0 Caffeine and tobacco use using the practice of smoking to control body weight is not recommended as too many health risks are increased 0 Decrease 0 Low calorie intake decreases basal metabolism by about 10 to 20 about 150 to 300 kcal per day 0 Aging I As lean body mass slowly and steadily decreases BMR declines 1 to 2 for each decade past 30 Define Direct and indirect calorimetry 0 Direct calorimetry A method of determining a body s energy use by measuring heat released from the body An insulated chamber is usually used 0 AKA the amount of body heat released by a person 0 Person is put in an insulated chamber often the size of a small bedroom and the body heat released raises the temperature of a layer of water surrounding the chamber 0 A kcal is related to the amount of heat required to raise the temperature of water 0 By measuring the water temperature in the direct calorimeter before and after the body releases heat scientists can determine energy expended 0 Indirect calorimetry A method to measure energy use by the body by measuring oxygen uptake Formulas are then used to convert this gas exchange value into energy use More common Measures the amount of oxygen a person consumes instead of heat output A predictable relationship exists between the body s use of energy and oxygen Instruments to measure oxygen consumption for indirect calorimetry are widely used They can be mounted on carts and rolled up to a hospital bed or carried in backpacks while a person plays tennis or jogs 0 There are even newly developed handheld instruments body gem Calculating an estimate of Total Energy Expenditure TEE 0 Total Energy Expenditure BMR Physical Activity TEF o BMR 60 to 70 0 Physical Activity 20 to 35 o TEF 5 to 10 0 Estimated Energy Requirement Calc for Men 19 years and older 0 BER 622 953 X AGE PHYSICAL ACTVITY X 1591 WEIGHT 5396 HEIGHT 0 Estimated Energy Requirement Calc for Women 19 years and older 0 BER 354 691 AGE PHYSICAL ACTIVITY 936 WEIGHT 726 HEIGHT OOOO Activity Level PA Men PA Women Sedentary e g no exercise 100 100 Low Activity eg walks the 111 112 equivalent of 2 miles per day to 3 to 4 mph Active eg walks the equivalent 125 127 of 7 miles per day at 3 to 4 mph Very Active eg walks the 148 145 equivalent of 17 miles per day at 3 to 4 mph EER Estimated Energy Requirement Age Age in years PA Physical Activity Estimate chart below WT weight in kilograms Pounds 22 HT Height in meters Inches 394 Characteristics of Healthy Body Weight Appropriate for your age Maintained without constant dieting Acceptable to you Is based on family history of body shape and weight Promotes good eating habits and allows for regular physical activity Low risk for diseases of obesity Overall the individual under a physician s guidance should establish a personal healthy weight or needed for weight reduction based on weight history fat distribution patterns family history of weight related disease and current health status Define Underweight overweight obesity and morbid obesity Underweight having too little body fat to maintain health Overweight having a moderate amount of excess body fat Obese having an excess of body fat that adversely affects health Morbid obesity body weight exceeding 100 of normal creating a very high risk for serious health complications Define BMI and the relationship with morality Body Mass Index BMI weight in kilograms divided by height in meters squared a value of 25 and above indicates overweight and a value of 30 and aboive indicates obesity BMI weight lbsl height inA2 x 703 or Weight in kilograms Height in meters quot2 Healthy weight 185 to 249 Over weight 25 to 299 Obese 30 to 399 Morbidly Obese 40 or greater Methods to assess body composition Body Composition Measurement of body fat and lean muscle mass Can be measured by O Underwater weighing 0 Skinfold measurements O Bioelectric impedance analysis 0 Near infrared reactance O Bod PodTM 0 Underwater weighing a method od estimating total body fat by weighing the individual on a standard scale and then weighing him or her again submerged 11 water The difference between the two weights is used to estimate total body volume 0 Most accurate 0 Air displacement BodyPod A method of estimating body composition tht makes use of the volume of space taken up b a body inside a small chamber 0 Once body volume is known it can be used along with body weight in the following equation to calculation body density 0 Body Density Bod weight body volume then using body density boy fat content can be determined by 496 body density 450 0 Skinfold thickness is also a common anthropometric method to estimate total body fat content although there are some limits to its accuracy 0 Bioelectrical impedance the method to estimate total body fat that uses a low energy electrical current The more fat storage a person has the more impedance resistance to electrical ow will be eXhibited O Painless low energy electrical current to and from the body via wires and electrode patches to estimate body fat 0 This estimation is based on the assumption that adipose tissue resists electrical ow more than lean tissue because it has a lower electrolyte and water content than lean tissue 0 Body composition monitors better known as body fat calculators that use bioelectric impendence are now available for home use 0 Similar to bathroom scales but measure fat 0 Duel Energy X Ray absorptiometry DEXA highly accurate method of measuring bod composition and bone mass and density using multiple low energy X rays Body Fat Patterning distribution and disease risk 0 Upperbody Apple Shaped The type of obesity in which fat is stored primarily in the abdominal area 0 Defined as a waist circumference more than 40 inches 102 cm in men and more than 35 inches 89 cm in women 0 Closely associated for high risk cardiovascular disease hypertension and type 2 diabetes Known as android obesity 0 High blood testosterone male hormone levels apparently encourage upper body obesity as does a diet with high glycemic load alcohol intake and smoking 0 0 Lowerdensity obesity Pear Shaped The type of obesity in which fat storage is primarily located in the buttocks and thigh area 0 Known as gynoid or gyecoid obesity 0 No significant increased risk for chronic diseases 0 Estrogen and progesterone female hormones encourage lower body fat storage Strengths and limitations of evaluating body fat BMI Gives ratio of weight to height Does not indicate pattern of fat or amount of fat or lean Accurately predicts risks tissue for an individual related to obesity in larg Does not account for grougs of people differences in gender frame size or activity level Body Composition If done properly the most Can be expensive accurate way to measure Not allways available body fat Fat Patterning Waist girth and waist to hip NOT a direct measure of ratio indicate fat distribution body fat content Relationship with disease risk Requires anthropometric is strong skillls TRENDS IN THE REVALENCE OF OBESITY OVER THE PAST 40 YEARS Percent Percent 40 rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr 40 196062 197174 197680 1 98894 199900 20034 05 6 Health problems associated with excess body fat 0 Type 2 diabetes 0 Hypertension 0 Gallstones 0 Cardiovascular disease 0 Various Cancers 0 Kidney gallbladder colon rectum uterus prostate breast 0 Surgical risk 0 Pulmonary disease sleep disorders 0 Bone and joint disorders 0 Pregnancy risks 0 Menstrual irregularities 0 Premature Death Sound Weight Loss Plan 1 Control of calorie intake One recommendation is to decrease calorie intake by 100 kcal per day increase physical actiVity by 100 kcal per day this sound allow for slow and steady weight loss 2 Increased physical actiVity 3 Acknowledgement that maintenance of a healthy weight requires lifelong changes in habits not a short term weight loss period Chapter 12 Micronutrient Function in Energy Metabolism and Blood Health Typical intake of B Vitamins in North America 0 Typical diet is adequate in B Vitamins 0 Common foods are fortified with B Vitamins O Ready to eat breakfast cereals 0 Water soluble any excess ends up in urine or stool and little is stored Chapter 12 Micronutrient Function in Energy Metabolism and Blood Health Typical intake of B Vitamins in North America 0 Typical diet is adequate in B vitamins 0 Common foods are fortified with B Vitamins O Ready to eat breakfast cereals 0 Water soluble any excess ends up in urine or stool and little is stored O 10 to 25 loss in food processing and preparation because they dissolve in water 0 Stir fry steaming and microwaving best 0 Alcoholics most likely to develop serious B vitamin deficiency diseases 0 Manufacturing and refining reduces B vitamin content of foods 0 Marginal deficiencies of these vitamins may occur in some cases especially among older adults who eat little food and in people with poor dietary patterns 0 Short run people with deficiency leads only to fatigue 0 Long term are unknown cardiovascular disease cancer and cataracts is suspected 0 North American diets have pretty good B vitamins except in cases of poverty metabolic disorder or alcoholism 0 Four B vitamins are 0 Thiamin 0 Ribo avin 0 Niacin Folic acid Coenzyme and impact of Vitamin B deficiency adequacy or excess 0 Coenzyme An organic compounds that combine with an inactive enzyme to form a catalytically active form In this manner coenzyme function 0 The B vitamin yield no energy directly but they contribute to energy yielding chemical reactions in the body b virtue of their coenzyme functions 0 B vitamins are coenzymes in metabolism minerals are cofactors in metabolism 0 Deficiencies affect brain nervous amp GI systems metabolically active tissues 0 50 90 B vitamins from diet are absorbed Five Watersoluble Vitamins and coenzyme forms involved in the oxidation of fuels to obtain energy intake and protein intake 1 Thiamin B1 2 Ribo avin B2 3 Niacin 4 Biotin 5 Pantothenic Acid Water soluble Vitamins for which can be expressed relative to energy intake and protein intake 0 Protein intake 0 Pyridoxine 0 Energy intake 0 Thiamin O Ribo avin Watersoluble Vitamin that can be formed in the body from tryptophan 0 Niacin Deficiency diseases for thiamin niacin and pyridoxine 0 Thiamin Beriberi 0 Niacin Pellagra 0 Pyridoxine Key function of Vitamin B6 0 Synthesize nonessential amino acids via transamination Iron role in oxygen transport 0 A component of the protein hemoglobin which carries oxygen in erythrocytes 0 A component of myoglobin which carries oxygen in muscle cells 0 A cofactor involved in energy metabolism of carbohydrates fats and proteins Irondeficiency anemia and perniciousmacrocytic anemia 0 Anemia means without blood any condition resulting in a decline in oxygen carrying capacity of the blood per unit volume 0 Iron Deficiency anemia 0 Iron deficiency results in small red blood cells that do not carry enough hemoglobin 0 Symptoms are fatigue pale skin impaired work performance depressed immune function impaired memory 0 Risk Women of childbearing age 0 Pernicious Vitamin B 12 Macrocytic anemia folate deficiency I look the same 0 Pernicious anemia unique effect on RBC 0 Nerve degeneration and paralysis takes some time to develop not completely reversible Zinc Functions and atrisk population 0 Cofactor for many enzymes including for hemoglobin production 0 Part of superoxide dismutase antioxidant enzyme system 0 Development and function of immune system 0 AT RISK Old people
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