Final Review and Assessment of Profile and Nutritional Health – FSM 159 Nutrition - 30 points After you have completed your IProfile analysis and your personal iProfile questions - you must now review

Chapter 9 Energy Balance and Weight Management Body Weight and Health • Overweight: being too heavy for one’s height, usually due to an excess of body fat. o Body mass index of 25 to 29.9 kilograms/meter 2. • Obese: having excess body fat. o Body mass index of 30 kg/m 2 or greater. • Globesity: reflects the escalation of obesity world wide. • In the United States: 70 % of adults are overweight or obese. o The obesity rates for minorities exceed those of the general population. ▪ African Americans: 48.4 % are obese. ▪ Hispanic Americans: 42.6 % are obese. Why Are We Getting Fatter? • Obesogenic environment: promotes weight gain and is not conducive to weight loss. • Eating more: constantly bombarded with cues to eat. o Advertisements; tasty, inexpensive foods; convenience stores; food courts; and vending machines. • Appetite: a desire to consume specific foods that is independent of hunger. o Triggered by external cues such as sight or smell of food. • Hunger: a desire to consume food that is triggered by internal phy siological signals. • Portion sizes have increased. o The more food put in front of people, the more they eat. • Social changes have contributed to the increase in the number of calories consumed. o Busy schedules. o Increase in single -parent households or household s with two working parents. o Prepackaged, convenience, and fast -food meals have become more common. • Moving less: decline in the amount of energy Americans expend at work and at play. o Labor saving devices; driving to work, elevator instead of stairs, etc. o Us e of television, video games, tablets, and computers has increased. o Inactivity is also contributing to excess body weight among children. What’s Wrong with Having Too Much Body Fat? • Having too much body fat increases a person’s risk of developing chronic health problems. o Includes: high blood pressure, heart d isease, high blood cholesterol, diabetes, asthma and breathing problems, gallbladder disease, liver disease, arthritis, sleep disorders, respiratory problems, and menstrual irregularities . o Cancers of t he breast, uterus, prostate, and colon. • Obesity increased the incidence and severity of infectious disease. o Has been linked to poor wound healing and surgical complications. • The more excess body fat, the greater the health risks. • The longer excess body fat is present, the greater the risks. • Excess weight at a younger age and remaining overweight throughout life, the greatest health risk. • Being overweight also has psychological and social consequences. o More l ikely to experience depression . o May be discrimi nated against in college admissions, in the workplace, and on public transportation. • Obesity increases health care costs. What Is a Healthy Weight? • A healthy weight is a weight that minimizes health risks. • Lean body mass: body mass attributed to nonfat bo dy components such as bone, muscle, and internal organs. o Also called: fat -free mass. • Body mass index (BMI): a measure of body weight relative to height. o Current standard for assessing the healthfulness of body weight. o Underweight: BMI of <18.5 kg/m 2 o Healthy: BMI of 18.5 -24.9 kg/m 2 o Overweight: BMI of ≥25 and <30 kg/m 2 o Obese: BMI of ≥30 kg/m 2 o Extreme or morbid obesity: ≥40 kg/m 2 o Useful tool but other information needed to assess health risk . ▪ In muscular athletes, BMI does not provide an accurate estimate of health risk. • Body composition: relative proportions of fat and lean tissue. o Healthy level of body fat: ▪ Women tend to store more body fat than men . ▪ Young adult females: 21 -32% of total weight. ▪ Young adult males: 8 -19% of total weight. o Underwater weighing: relies on the fact that lean tissue is denser than fat disuse. The difference between a person’s weight on land and his/her weight in water is used to calculate body density; the higher the density, the less fat he/she has. ▪ Can’t be used for sma ll children or ill, frail adults. o Skinfold thickness: uses calipers to measure the thickness of the fat layer under the skin at several locations. ▪ Assumes that the amount of fat under the skin is representative of total body fat. ▪ Fast, easy, and inexpensiv e. ▪ Should be performed by a trained professional for accuracy . o Air displace ment: measures air displacement in a closed chamber to determine body density. ▪ Accurate and easy for the subject. ▪ Expensive and not readily available. o Bioelectrical impedance: measu res an electrical current traveling through the body. ▪ Based on the fact that current moves easily through lean tissue, which is high in water, but is slowed by fat, which resists current flow. ▪ Fast, easy, and painless. ▪ Can be inaccurate if the amount of body water is higher or lower than typical. o Dual energy X -ray absorpti ometry (DXA): distinguishes amo ng various body tissues by measuring differences in levels of X -ray absorption. ▪ Can accurately determine total body mass, bone mineral mass, and body fat percentage. ▪ Expensive and not readily available. • Locations of body fat o Subcutaneous fat: adipose tissue located under the skin. ▪ Does not increase health risk as much as excess visceral fat. o Visceral fat: adipose tissue located around internal organs in the abdomen. ▪ More metabolically active than subcutaneous fat. ▪ Associated with a higher incidence of heart disease, high blood cholesterol, high blood pres sure, stroke, diabetes, and some types of cancer. ▪ More common in men than in women. ▪ After menopause, the amount of visceral fat in women increases. ▪ Increases with age. ▪ Stress, tobacco use, and alcohol consumption predispose people to visceral fat storage. o Where fat is deposited is determined primarily by genes. ▪ Age , gender, ethnicity, and lifestyle also i nfluence fat storage. Energy Balance • Energy balance: the amount of energy consumed in the diet compared with the amount expended by the body over a given period of time. Balancing Energy Intake and Expenditure • Energy Intake: the amount of energy consumed from foods and beverages. • Total energy expenditure: the amount of energy used by the body each day. • Basal metabolism: the energy expended to maintain an awake, resting body that is not digesting food. o For most people, 60 -75% of total energy expend iture is for basal metabolism. o Basal metabolic rate: the rate of energy expenditure under resting conditions. ▪ It is measured after 12 hours without food or exercise. o Increases with increasing body weight. o Lean tissue takes more energy to maintain than fat tissue. o Generally higher in men than in women. o Decreased with age, partly due to a decrease in lean body mass. o Lower when calorie intake is consistently below the body’s needs. o Factors that increase basal metabolism: ▪ Higher lean body mass. ▪ Greater height and weight. ▪ Pregnancy or lactation. ▪ Growth. ▪ Low calorie diet. ▪ Starvation. ▪ Fever. ▪ Low thyroid hormone levels . ▪ Stimulant drugs such as caffeine and tobacco. ▪ Exercise. • Physical activity: second major component of total energy expenditure. o Average: 15 -30% of energy requirements. • Non -exercise activity thermogenesis (NEAT): the energy expended for everything we do other than sleeping, eating, or sports -like exercise. o Depends on individual’s occupation and daily movements. o Depends on the size of the person , how strenuous the activity is, and the length of time it is performed. • Thermic effect of food (TEF) or diet -induced thermogenesis: the energy required for the digestion of food and absorption, metabolism, and storage nutrients. o Estimated to be about 10% of total energy intake. o Depends on the amounts and types of nutrients consumed. o A bigger meal produces a greater thermic effect of food. o A high -fat meal yields a lower TEF than one high in carbohydrate or protein. • The basics of weight gain and w eight loss. o If more energy is consumed than expended, the excess energy is stored for later use. o A small amount of energy is stored as glycogen in liver and muscle. o Adipocytes: cells that store fat as triglycerides . ▪ Can increase in size to accumulate more fat; can shrink as fat is removed. ▪ The larger the number, the greater the body’s ability to store fat. ▪ Most adipocytes are formed during infancy and adolescence. ▪ Excess weight gain can cause the formation of new adipocytes. o Stored energy is used when ener gy intake is low . o An energy deficit of about 3500 Calories results in the loss of a pound of adipose tissue. Estimated Energy Requirements • Estimated Energy Requirement (EER): the number of calories needed for a healthy individual to maintain his/her weight. o Calculated using equations that take into account gender, age, height, weight, act ivity level, and life stage. o Need to know physical activity (PA) value What Determines Body Size and Shape? • Genes determine body size and shape. • There are many genes that have been linked to obesity. • Environment and l ifestyle choices also play an important role in determining body weight and size . Genes vs. Environment • If one or both parents are obese, your risk of obesity increases with the magnitude o f the obesity . • Through twin studies, determined about 40 -70% of the variation in BMI between individuals can be attributed to genes. • Remaining amount is determined by your environment and lifestyle choices. Regulation of Food Intake and Body Weight • Set -point: the body compensates for variation in diet and exercise by adjusting energy intake and expenditure to keep weight at a particular level. o Determined in part by genes. • Satiety: the feeling of fullness and satisfaction caused by food consumption th at eliminates the desire to eat. Regulating how much we eat at each meal • Physical sensations of hunger or satiety are triggered by signals from the gastrointestinal tract, levels of nutrients, and hormones circulating in the blood, and messages from the brain. • Ghrelin: hormone produced by the stomach; stimulates the desire to eat at usual mealtimes. o Blood levels of ghrelin rise an hour or two before a meal and drop very low after a meal. • Peptide YY : hormone that causes a reduction in appetite. o Released fro m the gastrointestinal tract after a meal. o The amount released is proportional to the number of calories in the meal. • Psychological factors affect hunger and satiety. o Some people eat for comfort or to relieve stress. o Others lose their appetite when under s tress. Regulating body fat over the long term • Leptin: hormone produced by the adipocytes. o The amount produced is proportional to the size of the adipocytes that regulates body fatness in the long term . o The effect of leptin on energy intake and exp enditure depends on the amount releas ed. o Better at preventing weight loss than preventing weight gain. o Obese individuals generally have high levels of leptin, but this is not effective in reducing calorie intake and increasing energy expenditure. What a S cientist Sees: Leptin and Body Fat What might happen to someone who does not produce enough leptin? How about a person with a defect that causes overproduction of leptin? Why Do Some People Gai n Weight More Easily ? • Mutations in single genes are not responsible for most human obesity. • Some people may gain weight more easily because they inherited genes that make them more efficient at using energy and storing fat. • Some people may gain weight more easily because they inherit a tendency to expend less e nergy on activity. Managing Body Weight • Make healthy food choices. • Control portion sizes. • Maintain an active lifestyle. Weight -Loss Goals and Guidelines • To lose 1 pound per week, energy balance must be negative by about 500 Calories per day. • A loss of 10% of body weight will significantly reduce disease risk. • Lose weight slowly: rate of ½ to 2 lbs/week. o Helps ensure that most of what is lost is fat and not lean tissue. • Successful long -term weight management involves a combination of decreasing intake, increasing activity, and changing the behavior patterns that led to weight gain. Decreasing energy intake • Intake must be low in energy but high in nutrients. • If consuming less than 1200 Calories/day, a multivitamin/multimineral supplement is recom mended. • Medical supervision is recommended if intake is below 800 Calories/day. Increasing physical activity • Exercise increases energy expenditure, making weight loss easier. • Exercise promotes muscle development. o Muscle is metabolically active tissue. o Inc reased muscle mass increases energy expenditure. • Physical activity improves overall fitness and relieves boredom and stress induced weight gain . • Recommend ed that adults engage in the equivalent of 150 minutes of moderate - intensity aerobic activity per week . o This amount varies; s ome individuals may need the equivalent of 300 minutes of moderate -intensity activity each week to maintain body weight. What Should I Eat? Balance Your Intake and Output • Balance your intake and output. • Moderate your intake . • Expand your expenditure . Modifying behavior • Behavior modification: a process that is used to gradually and permanently change behaviors. • ABCs of behavior modification: o Identify the antecedents . o Recognize the behavior. o Fee l the consequences. o Modify the beh avior. o Enjoy the new consequences. Managing America’s weight • We need strategies that can help Americans improve their food choices, reduce portion sizes, and increase physical activity. • Food manufacturers and restaurants: healthier options, smaller port ions. • Communities: parks, bike path, and recreational facilities. • Business and schools: opportunities for physical activity during the day. Suggestions for Weight Gain • Medical evaluation to rule out medical reasons for low body weight. • Gradually increase consumption of energy dense foods. • Eat more frequently. • Muscle s trength en ing exercises Diets and Fad Diets • Any diet that reduces energy intake will promote weight loss. • True test of the effectiveness of a weight loss plan: whether it promotes wei ght loss that can be maintained over the long term. • Selecting a weight loss plan: o Based on sound nutrition and exercise principles. o Suits your individual preferences of food choices. o Time and c ost. o Promotes long -term lifestyle changes. • Common methods for reducing calorie intake: o Food guides for diet planning (i.e. MyPlate) . o Eating pre -packaged meals or liquid meals. o Reduce fat and carbohydrate content in diet. Think It Through: A case study on food choices and body weight Weight -Loss Drugs and Supplements • Prescription drugs . o Approved by FDA. o Reduce appetite and increase sense of fullness . ▪ Lorcaserin . ▪ Phentermine . o Decrease the absorption of fat in the intestine. ▪ Orlistat . o Recommended only for those whose health is compromised by their body weight. o Disadvantage: weight is usually regained when the drug is discontinued. • Over -the -Counter drugs. o Also regulated by the FDA and must adhere to strict guidelines. ▪ Ver sion of Orlistat (Alli). • Weight -Loss Supplements. o Not strictly regulated by FDA. o Herbal products: often contain prescription drugs or compounds that have not been adequately studied in humans . o Soluble fiber: reduce the amount eaten by filling up the stomach. ▪ Safe. ▪ Promote only a small amount of weight loss. o Supplements that promise to enhance fat loss by altering metabolism to prevent the synthesis and deposition of fat. ▪ Examples: hydroxycit ric aci d, conjugated linoleic acid, and chromium picolinate. ▪ None shown to be effective in humans. o Fat burners. ▪ Boost energy expenditure. ▪ Can be effective. ▪ Have serious and life -threatening side effects. ▪ Example: ephedra. • Banned by the FDA in 2004. ▪ Typically contain guarana, an herbal source of caffeine. ▪ Green tea extract. • Source of caffeine and phytochemicals • Small effect on weight loss . • Associated with liver damage. o Diuretics. ▪ Lose weight through water loss not decrease in body fat. o Herbal laxatives. ▪ Overuse can have serious side effects. Think Critically : Alli: Blocking Fat Absorption • Question: Will Alli be an effective weight -loss aid for someone eats a low fat diet ? Why or why not? Weight -Loss Surgery • Surgical procedures to decrease body weight by altering the gastrointestinal tract so as to reduce food intake and absorpti on. • Recommended only in cases of extreme obesity. • Gastric bypass: surgical procedure that reduces the size of the stomach and bypasses a portion of the small intestine. • Adjustable gastric banding: surgical procedure in which an adjustable band is placed around the upper portion of the stomach to limit the volume that the stomach can hold and the rate of stomach emptying. • Liposuction: surgical procedure to remove a fat deposit under the skin. o Considered a cosmetic procedure. o Does not significantly reduce overall body weight. DEBATE: Is surgery a good solution to obesity? • When conventional methods to lose weight do not work does the risk of surgery outweigh the benefits? Eating Disorders • A psychological illness characterized by spec ific abnormal eating behaviors, often intended to control weight. • When the emotional aspects of food and eating overpower the role of food as nourishment . • Affect phys ical and nutritional health and psychosocial functioning . • If left untreated, they can be fatal. Types of Eating Disorders • Anorexia nervosa: characterized by self -starvat ion, a distorted body image, abnormally low body weight , and a pathological fear of becoming fat . • Bulimia nervosa: characterized by the consumption of a large amount of food a t one time (binge eating) followed by purging behaviors such as self -induced vomiting to prevent weight gain. • Binge -eating disorder: characterized by recurring episodes of binge eating accompanied by a loss of control ove r eating in the absence of purging behavior. What Causes Eating Disorders? • Genetic, psychological, and sociocultural factors contribute to their development. • Can be triggered by traumatic events. o Sexual abuse. o Day -to -day occurrences: teasing or judgmental comments. • Occur in people of all ages, races, and socioeconomic backgrounds. o Women are more likely than men to develop eating disorders; however the number of men with eating disorders is increasing . o Those who are concerned with maintaining a low body weight: dancers, models. o Commonly begin in adolescence. • Psychological issues. o Body image: the way a person perceives and imagines his/her body. o People with eating disorders often have low self -esteem. o Distorted body image. o Often perfectionists who set very high standards for themselves an d strive to be in control of their bodies and their lives. o May feel inadequate, defective, and worthless. o May use their relationship with food to gain control over their lives and boost their self -esteem. • Sociocultural issues. o Cultural ideals about body si ze are linked to body image and incidence of eating disorders. o Occur in societies where food is abundant and the body ideal is thin. ▪ Do not occur in societies where food is scarce. o Media messages. Anorexia Nervosa • Characterized by distorted body image, excessive dieting, and pathological fear of being fat. • Affects about 1% of female adolescents in the US. • Death rate: 5 in 1000 people per year; 1 in 5 of those commit suicide. • Psychological component: overwhelming fear of gaining weight. o Feel they would rather be dead than fat. o Disturbances in body image. • Behaviors associated with anorexia nervosa: o Restriction of food intake. o Binge -eating and purging in some individuals. o Strange e ating rituals. o Excessive activity. • Symptoms: o Weight loss with sym ptoms of starvation. o Apathetic, dull, exhausted, and depressed. o Muscle wasting. o Inflammation and swelling of the lips. o Flaking and peeling of the skin. o Lanugo hair. o Females: estrogen levels drop and menstruation is irregular or stops. o Males: testosterone levels decrease. o Abnormalities in electrolyte and fluid balance and cardiac irregularities. o Suppression of immune function. • Goal of treatment: o Resolve the underlying psychological and behavioral problems. o Provide physical and nutritional rehab ilitation. Bulimia Nervosa • Characterized by an intense fear of becoming fat and a negative body image. o Accompanied by a distorted perception of body size. o Blame all of their problems on their appearance. o Preoccupied with the fear that once they start eati ng, they will not be able to stop. o Engage in continuous dieting and preoccupation with food. o Often socially isolated and avoid situations that will expose them to food. o Typically begins with food restriction motivated by a desire to be thin. ▪ Overwhelming h unger leads to a period of overeating. ▪ Pattern of semi -starvation interrupted by period of gorg ing. o Binges usually last less than 2 hours and occur in secrecy. o Use behaviors to eliminate extra calories and prevent weight gain: ▪ Fasting. ▪ Excessive exercise. ▪ Vomiting. ▪ Taking laxatives, diuretics or other medications. • Goals of therapy: o Reduce or eliminate binge ing and purging behavior. o Resolve psychological issues related to body image. o Nutritional therapy to address physiological imbalances. o Educatio n. Binge -Eating Disorder • Most common eating disorder. • Affects both genders. o Men account for 40% of the cases. • Engage in recurrent episodes of binge eating but do not engage in purging behaviors. • Complications: health problems associated with obesity. • Trea tment: o Counseling to improve body image and self -acceptance. o Nutritious low -calorie die t. o Increased exercise to promote weight loss. o Behavior therapy to reduce bingeing. Eating Disorders in Special Groups • Anorexia athletic a: athletes • Avoidant/restrictive food intake disorder: infant, children, and adults. • Insulin misuse (diabulimia): people taking insulin to control diabetes. • Female athlete triad: female athletes in weight -dependent sports. • M uscle dysmorphia (megarexia or reverse anore xia ): bodybuilders and avid gym -goers. o More common in men than women. • Night -eating syndrome: obese adults and those experiencing stress. • Pica: pregnant women, children, people whose family or ethnic customs include e ating certain nonfood substance s. • Rumination Disorder: infants, adolescents, and adults. • Selective eating disorder: children. Preventing and Getting Treatment for Eating Disorders • Prevention: o Elimination of weight -related criticism. o Change media images and messages away from an unrealistically thin body. o Education through schools and communities. o Recognize who may be at risk. o Early intervention.