Nutrition in Weight Management PDF

Nutrıtıon ın Weıght Management  Body weight is the sum of bone, muscle, organs, body fluids, and adipose tissue. Some or all of these components are subject to normal change as a reflection of growth, reproductive status, variation in physical activity, and the effects of aging. Consiste...

Nutrıtıon ın Weıght Management  Body weight is the sum of bone, muscle, organs, body fluids, and adipose tissue. Some or all of these components are subject to normal change as a reflection of growth, reproductive status, variation in physical activity, and the effects of aging. Consistent body weight is orchestrated by neural, hormonal, and chemical mechanisms as well as individual genetic polymorphisms that balance energy intake and expenditure within fairly precise limits. Abnormalities of these complex mechanisms can result in weight fluctuations. BODY WEIGHT COMPONENTS Body weight often is described in terms of its composition Traditionally, a two-compartment model divides the body into fat mass, the fat from all body sources including the brain, skeleton, and adipose tissue, fat-free mass (FFM), which includes water, protein, and mineral components The proportions of FFM are relatively constant from person to person. Lean body mass (LBM) Although FFM often is used interchangeably with the term lean body mass, it is not exactly the same. Lean body mass (LBM) is muscle. LBM is higher in men than in women, increases with exercise, and is lower in older adults. It is the major determinant of the resting metabolic rate (RMR). It follows that a decrease in LBM could hinder the progress of weight loss. Therefore, to achieve long-term weight loss, the loss of fat mass while maintaining FFM is desirable. Water, which makes up 60% to 65% of body weight, is the most variable component of LBM, and the state of hydration can induce fluctuations of several pounds.  Total body fat is the combination of “essential” and Body Fat “storage” fats, usually expressed as a percentage of total body weight that is associated with optimum health. Essential fat, necessary for normal physiologic functioning, is stored in small amounts in the bone marrow, heart, lung, liver, spleen, kidneys, muscles, and the nervous system. In men, approximately 3% of body fat is essential. In women, essential fat is higher (12%) because it includes body fat in the breasts, pelvic regions, and thighs that supports the reproductive process.  Storage fat is the energy reserve, primarily as triglycerides (TGs), in adipose tissue. This fat accumulates under the skin and around the internal organs to protect them from trauma. Most storage fat is “expendable.” The fat stores in adipocytes are capable of extensive variation. This allows for the changing requirements of growth, reproduction, aging, environmental and physiologic circumstances, the availability of food, and the demands of physical activity. Total body fat (essential fat plus storage fat) as a percentage of body weight associated with the average individual is between 18% and 24% for men and 25% and 31% for women. On the other extreme, “elite fit” men are as low as 2% to 5% body fat and women 10% to 13%  Total body fat (essential fat plus storage fat) as a percentage of body weight associated with the average individual is between 18% and 24% for men and 25% and 31% for women. On the other extreme, “elite fit” men are as low as 2% to 5% body fat and women 10% to 13%. Adipose Tissue Composition  Adipose tissue exerts a profound influence on whole-body homeostasis. Adipose tissue is located primarily under the skin, often referred to as visceral adipose tissue (VAT). Although it is primarily fat, adipose tissue also contains small amounts of protein and water. White adipose tissue (WAT) stores energy as a repository for TGs, cushions abdominal organs, and insulates the body to preserve heat. Carotene gives it a slight yellow color.  Brown adipose tissue (BAT) can be found in a substantial proportion of adults in small amounts as well as in infants. nlike WAT, BAT is made of small droplets and many more iron containing mitochondria, which makes it brown. In adults, it plays a role in controlling energy expenditure. In newborns, it provides body heat. Although WAT stores energy, BAT helps regulate body temperature by regulating heat. It is found mainly in scapular and subscapular areas.  The mature fat cell (adipocyte) consists of a large central lipid droplet surrounded by a thin rim of cytoplasm, which contains the nucleus and the mitochondria. Adipocyte Size These cells can store fat equal to 80% to 95% of their volume. and Number Gains in weight and adipose tissue occur by increasing the number of cells, the size of cells as lipid is added, or a combination of the two.  Hyperplasia (increased number of cells) occurs as a normal growth process during infancy and adolescence. Cell number increases in lean and obese children into adolescence, but the number increases faster in obese children. In teens and adults, increases in fat cell size are more common, but hyperplasia also can occur after the fat content of existing cells has reached capacity.  During normal growth, the greatest percentage of body fat (approximately 25%) is set by 6 months of age. In lean children, fat cell size then decreases; this decrease does not occur in obese children. At the age of 6 years in lean children, adiposity rebound occurs, especially in girls, with an increase in body fat. An early adiposity rebound occurring before five and a half years old is predictive of a higher level of adiposity at 16 years of age and in adulthood; a period of later rebound is correlated with normal adult weight.  With hypertrophy (increased cell size), fat depots can expand as much as 1000 times at any age, as long as space is available. weight loss as a result of trauma, illness, or starvation, that fat cell size decreases but cell numbers remain the same. Although weight loss of any amount in severely obese individuals improves basic adipocyte physiology, a weight loss of at least 5% is required to decrease fat cell size.  Fat Storage Most depot fat comes directly from dietary TGs. The fatty acid composition of adipose tissue mirrors the fatty acid composition of the diet. Even excess dietary carbohydrate and protein are converted to fatty acids in the liver by the comparatively inefficient process of lipogenesis. Under normal conditions, little dietary carbohydrate is used to produce adipose tissue; three times more energy is required to convert excess energy from carbohydrate to fat storage compared with dietary fat.  Semivolatile organic compounds (SVOCs) accumulate in adipose tissues from exposure to toxins, chemicals, and pesticides. When adipose tissue is mobilized during weight loss, SVOCs are released. Reading 1 Lipoprotein Lipase Dietary TG is transported to the liver by chylomicrons. Endogenous TGs, synthesized in the liver from free fatty acids (FFA) travel as part of very low–density lipoprotein particles. The enzyme lipoprotein lipase (LPL) moves lipid from the blood into the adipose cell, by hydrolyzing TGs into free fatty acids and glycerol. Glycerol proceeds to the liver; fatty acids enter the adipocyte and are reesterified into TGs. When needed by other cells, TGs are hydrolyzed once again to fatty acids and glycerol by hormone-sensitive lipase (HSL) within the adipose cell; they then are released into the circulation.  Hormones affect LPL activity in different adipose tissue regions. Estrogens stimulate LPL activity in the gluteofemoral adipocytes, and thus promote fat storage in this area for childbearing and lactation. In the presence of sex steroid hormones, a normal distribution of body fat exists. With a decrease in sex steroid hormones—as occurs with menopause or gonadectomy—central obesity tends to develop. REGULATION OF BODY WEIGHT Neurochemicals, body fat stores, protein mass, hormones, and postingestion factors play a role in regulating intake and weight. Regulation takes place on a short-term and a long-term basis. Short-term regulation governs consumption of food from meal to meal; long-term regulation is controlled by the availability of adipose stores and hormone responses. Short- and Long-Term Regulation Short-term controls are concerned primarily with factors governing hunger, appetite, and satiety. Satiety is associated with the postprandial state when excess food is being stored. Hunger is associated with the postabsorptive state when those stores are being mobilized. Physical triggers for hunger are much stronger than those for satiety; it is easier to override the signals for satiety.  When either overfeeding or underfeeding occurs, younger individuals exhibit spontaneous hypophagia (undereating) or hyperphagia (overeating) accordingly. Older individuals do not have the same responsiveness; they are more vulnerable to unexplained weight losses or gains because they are unable to control spontaneous, short-term changes in food intake.  Long-term regulation seems to involve a feedback mechanismin which a signal from the adipose mass is released when“normal” body composition is disturbed, as when weight lossoccurs. Adipocytokines or adipokines are proteins released by the adipose cell into the bloodstream that act as signaling molecules. Younger persons have more responsiveness to this feedback than older adults do. Reading 2. Set Point Theory Fat storage in non-obese adults appears to be regulated in a manner that preserves a specific body weight. In animals and humans, deliberate efforts to starve or overfeed are followed by a rapid return to the original body weight, a “set point.” According to the set point theory, body weight remains remarkably stable from internal regulatory mechanisms that are genetically determined. WEIGHT IMBALANCE: OVERWEIGHT AND OBESITY Obesity Overweight occurs as a result of an imbalance between food consumed and physical activity. Obesity is a complex issue related to lifestyle, environment, and genes. Environmental and genetic factors have a complex interaction with psychologic, cultural, and physiologic influences. Prevalence Until recently, the United States has had the highest prevalence of obesity among the developed nations. However, increases in the prevalence of overweight and obesity have been observed throughout the world. The internationaltrend often is called “globesity.” Genetics Many hormonal and neural factors involved in weight regulation are determined by heredity and genetics. These include short-term and long-term “signals” that determine satiety and feeding activity. Small defects in their expression or interaction could contribute significantly to weight gain. Nutritional genomics is the study of the interactions between dietary components and the instructions in a cell or genome, and the resulting changes in metabolites that affect gene expression.  The number and size of fat cells, regional distribution of body fat, and RMR also are influenced by genes. Studies of twins confirm that genes determine 50% to 70% of the predisposition to obesity. Although numerous genes are involved, several have received much attention: the Ob gene, the adiponectin (ADIPOQ) gene, the “fat mass and obesity associated” gene or FTO gene, the beta3-adrenoreceptor gene. Inadequate Physical Activity Lack of exercise and a sedentary lifestyle, compounded by chronic overeating, are also causes of weight gain. The sedentary nature of society is a factor in the growing problem of obesity. Fewer people are exercising, and more time is being spent in low- energy, screen-watching activities such as watching television or movies, using a computer or smartphone, playing video games, and sitting in cars driving to work or events. Inflammation Adipose tissue actively causes secretion of a wide range of pro- and anti-inflammatory cytokines. Effects include insulin insensitivity, hyperlipidemia, muscle protein loss, and oxidant stress. Scientists have found a direct relationship between obesity and inflammatory diseases such as cardiovascular disorders, some cancers, and type 2 diabetes.  Metabolic signals are triggered in the hypothalamus of obese individuals, laying the groundwork for chronic inflammation and tissue damage during a prolonged period. In humans, chronic overeating “flips on” the inflammation switch, leading to weight gain and insulin resistance. A simple dietary change to an antiinflammatory diet and lifestyle changes can alter obesity-related inflammation. Genotypic factors influence the effectiveness of immunonutrients; antioxidants and omega-3 polyunsaturated fatty acids decrease the intensity of the inflammatory process. Medication Usage and Weight Gain Although weight gain can be due to disease, therapists always should consider the possibility that the patient’s medication may be contributing. This often is seen with: diabetes medications, and psychotropic, antidepressant, steroid, and anti-hypertensive medications.  Sleep Stress, and Circadian Rhythms Shortened sleep alters the endocrine regulation of hunger and appetite. Hormones that affect appetite take over and may promote excessive energy intake. Thus recurrent sleep deprivation can modify the amount, composition, and distribution of food intake and may contribute to the obesity epidemic. People suffer from sleep deprivation or others may have shift work or exposure to bright light at night, increasing the disruption of circadian rhythms and enhancing the prevalence of adiposity. There is also a relationship between sleep, disrupted circadian rhythm, genes, and the metabolic syndrome. Stress is another factor. The cortisol hormone is released when an individual is under stress, and stimulates insulin release to maintain blood glucose levels in the “fight-or-flight” response. Thus an increase in appetite occurs. Chronic stress with constantly elevated cortisol levels can also lead to appetite changes. Taste, Satiety, and Portion Sizes Food and its taste elements evoke pleasure responses. The endless variety of food available at any time at a reasonable cost can contribute to higher calorie intake; people eat more when offered a variety of choices than when a single food is available. Normally, as foods are consumed, they become less desirable; this phenomenon is known as sensory-specific satiety. Although sensory-specific satiety can promote the intake of a varied and nutritionally balanced diet, it can also lead to overconsumption. Leptin is a hormone, made by fat cells, that decreases appetite. Ghrelin is a hormone that increases appetite and plays a role in body weight. Levels of leptin, the appetite suppressor, are lower in normal weight individuals and higher in the obese. However, many obese people seem to build up a resistance to the appetite-suppressing effects of leptin. Obesogens Obesogens are chemical compounds foreign to the body that act to disrupt the normal metabolism of lipids, ultimately resulting in fatness and obesity. Obesogens can be called “endocrine disruptors” in that they alter lipid homeostasis and fat storage, change metabolic set points, disrupt energy balance, or modify the regulation of satiety and appetite to promote accumulation of fat and obesity. Examples of suspected obesogens in the environment and food supply are bisphenol A (BPA) and phthalates, which are found in many plastics used in food packaging and which migrate into foods processed or stored in them. Viruses and Pathogens In the last two decades, at least 10 adipogenic pathogens have been identified, including viruses, scrapie agents (spongiform encephalopathies from sheep or goats), bacteria, and gut microflora. Whether “infectobesity” is a relevant contributor to the obesity epidemic remains to be determined. A human adenovirus, adenovirus-36, is capable of inducing adiposity in experimentally infected animals by increasing the replication, differentiation, lipid accumulation, and insulin sensitivity in fat cells and reduces leptin secretion and expression. Gut Microflora and Diet Research has identified a strong and complex relationship between the microflora population of the gut and food absorption. The microbes firmicutes and bacteriodetes, normally found in gut flora, are believed to have a symbiotic relationship, acting as either fattening or slimming microbiota, dependent on the person’s nutritional status, food intake, and ability to absorb food. Firmicutes bacteria tend to be much more efficient at nutrient breakdown and calorie absorption than bacteriodetes, and therefore contribute to calorie absorption and the development and maintenance of obesity in individuals. A higher number of bacteriodetes, on the other hand, may help to make or keep people lean. Weight loss, then, it appears would require a higher number of bacteriodetes and a lower number of firmicutes. Assessment  Overweight is a state in which the weight exceeds a standard based on height. Obesity is a condition of excessive fatness, either generalized or localized. Overweight and obesity usually parallel each other, but it is possible to be overweight according to standards but not be “overfat” or obese. It is also possible to have excessive fatness and yet not be overweight.  Clinically practical assessment tools are (1) the body mass index (BMI) or Body Fatness W/H2, in which W = weight in kg and H = height in meters, and (2) the waist circumference, Circumference (3) the neck circumference, Measurements (4) the waist-to-hip ratio, (4) waist-to-height ratio (5) the neck-to-waist ratio Body Mass Index- (BMI) the waist circumference Waist circumference of more than 40 inches (102) in men and more than 35 inches (88 cm) in women signifies increased risk, equivalent to a BMI of 25 to 34. When waist circumference and percentage of fat are both high, they are significant predictors of heart failure and other risks associated with obesity. Waist circumference is a strong correlate of insulin sensitivity index in older adults; measurement of waist circumference is helpful to assess disease risk. the waist-to-hip ratio Waist/hip ratio (WHR) is a measurement in which a ratio of more than 0.8 for women and 1 for men is also associated with high risk for cardiovascular events. Deurenberg Equation The Deurenberg equation using the BMI, age, and gender of an individual to determine body fatness is as follows (Deurenberg and Deurenberg-Yap, 2003): A body fat percentage of 20% to 25% or more in a male and 25% to 32% or more in a female usually is considered to be excessive and associated with the metabolic and health risks of obesity.  Athletes could weigh more from muscle mass, and their BMI would be higher because of it.  https://www.ncbi.nlm.nih.gov/books/NBK279167/ Health Risks In general, obesity can be viewed as metabolically unhealthy. Chronic diseases such as heart disease, type 2 diabetes, hypertension, stroke, gallbladder disease, infertility, sleep apnea, hormonal cancers, and osteoarthritis tend to worsen as the degree of obesity increases. Estimates using mortality data from the NHANES surveys show that thousands of deaths are related to obesity. Increased adiposity and reduced physical activity are strong independent risk factors for death in women.  Several large studies have determined that the optimal BMI with the least risk for mortality is a BMI of 23 to 24.9. BMI above or below this range seems to increase mortality risk. The optimal range for longevity appears to be within the range of 20.5 to 24.9. Overweight adolescents often become obese adults; obese individuals are at increased risk for comorbidities of type 2 diabetes, hypertension, stroke, certain cancers, infertility, and other conditions. Fat Deposition and the Metabolic Syndrome Regional patterns of fat deposit are controlled genetically and differ between and among men and women. Two major types of fat deposition currently are recognized: excess subcutaneous truncal-abdominal fat (the apple-shaped android fat distribution) excess gluteofemoral fat in thighs and buttocks (the pear-shaped gynoid fat distribution).  Women with the gynoid type of obesity do not develop the impairments of glucose metabolism in those with an android deposition. Postmenopausal women more closely follow the male pattern of abdominal fat stores, sometimes referred to as “belly fat.”  Abdominal fat is an indicator of fat surrounding internal organs or visceral fat. People with higher amounts of abdominal fat, versus fat in other parts of body, were found to have higher risks of cancer and heart disease. the metabolic syndrome (MetS) Visceral obesity, or excessive visceral adipose tissue (VAT) under the peritoneum and in the intraabdominal cavity, is correlated highly with insulin resistance and diabetes. Individuals diagnosed with the metabolic syndrome (MetS) have three or more of the following abnormalities: waist circumference of more than 102 cm (40 in) in men and more than 88 cm (35 in) in women, serum TGs of at least 150 mg/dl, high-density lipoprotein (HDL) level less than 40 mg/dl in men and less than 50 mg/dl in women, blood pressure 135/85 mm Hg or higher, fasting glucose 100 mg/dl or higher. Increased visceral fat is a risk factor for: coronary artery disease, dyslipidemia, hypertension, stroke, type 2diabetes, and MetS. Calorie Restriction and Longevity Balancing energy intake and energy expenditure is the basis of weight management throughout life. Lifestyle modification, and becoming aware of eating behavior triggers to manage them more effectively, is vital for permanent change to occur. A key recommendation is to prevent gradual weight gain over time, by making small decreases in overall caloric intake and increasing physical activity. Patterns of healthful eating and regular physical activity should begin in childhood and continue throughout adulthood.  Prolonged calorie restriction (CR) increases life span and slows aging in animals. Two biomarkers of longevity—fasting insulin level and body temperature— have been noted to be decreased by prolonged CR in humans. Proponents of CR for anti-aging believe that cutting calorie intake reduces aging and chronic disease development. In rodents with Alzheimer’s disease, heart disease, and stroke, decreased deterioration of nerves and increased nerve creation also was demonstrated with calorie restriction.  Unless clinical studies provide clear evidence of its utility, the wider use of CR in the human population cannot be justified, based on current data. Weight Discrimination Weightism !  MANAGEMENT OF OBESITY IN ADULTS Today, a chronic disease-prevention model incorporates lifestyle interventions and interdisciplinary therapies from physicians, dietitians, exercise specialists, and behavior therapists. 1) Goals of Treatment 2) Rate and Extent of Weight Loss 3) Lifestyle Modification Goals of Treatment The goal of obesity treatment should focus on weight management and attaining the best weight possible in the context of overall health. Maintaining present body weight or achieving a moderate loss is beneficial. Obese persons who lose even small amounts of weight (5% to 10% of initial body weight) are likely to improve their blood glucose, blood pressure, and cholesterol levels.  Health professionals must help their patients accept more modest, realistic weight loss goals. For example, actuarial tables support no benefit and possible harm from weight loss after age 65. In fact, in the obese elderly, sarcopenia (loss of muscle mass) is the greatest predictor of disability along with the inability to perform daily activities. Rate and Extent of Weight Loss Reduction of body weight involves the loss of protein and fat in amounts determined to some degree by the rate of weight reduction. A drastic reduction in calories resulting in a high rate of weight loss can mimic the starvation response. Tissue response to starvation is one of adaptation to an anticipated period of deprivation.  The classic starvation studies done by Keys (1950) found that during the first 10 days of a fast and after depletion of glycogen stores, approximately 8% to 12% of the energy expenditure is from protein, and the balance is from fat. As starvation progresses, up to 97% of energy expenditure is from stored TGs. Metabolic aberrations during starvation include bradycardia, hypotension, dry skin and hair, easy fatigue, constipation, nervous system abnormalities, depression, and even death.  Mobilizing fat, with more than twice the kilocalories of protein, is more efficient and also spares vital LBM. Steady weight loss over a longer period favors reduction of fat stores, limits the loss of vital protein tissues, and avoids the sharp decline in RMR that accompanies rapid weight reduction Weight loss goals Calorie deficits that result in a loss of approximately 0.5 to 1 lb (250 -500 g) per week for persons with a BMI of 27 to 35, 1 to 2 lb (500 g- 1kg) per week for those with BMIs greater than 35, should continue for approximately 6 months for a reduction of 10% of body weight. For the next 6 months the focus changes from weight loss to weight maintenance. After this phase, further weight loss may be considered. Even with the same caloric intake, rates of weight reduction vary. Men reduce weight faster than women of similar size because of their higher LBM and RMR. The heavier person expends more energy than one who is less obese and loses faster on a given calorie intake than a lighter person. Many obese persons who fail to lose weight on a diet actually consume more energy than they report and overestimate their physical activity levels. Lifestyle Modification Behavior modification is the cornerstone of lifestyle intervention. It focuses on restructuring a person’s environment, nutrient intake, and physical activity by using goal setting, stimulus control, cognitive restructuring, and relapse prevention. It also provides feedback on progress and places the responsibility for change and accomplishment on the patient. Stimulus control involves modification of (1) the settings or the chain of events that precede eating, (2) the kinds of foods consumed when eating does occur, and (3) the consequences of eating. Patients are taught to slow their rate of eating to become mindful of satiety cues, and reduce food intake. Strategies such as putting down utensils between bites, pausing during meals, and chewing for a minimum number of times are some ways to slow the eating process.  Problem solving is the process of defining the intake problem, generating possible solutions, evaluating and choosing the best solution, implementing the new behavior, evaluating outcomes, and reevaluating alternative solutions if needed. Cognitive restructuring teaches patients to identify, challenge, and correct the negative thoughts that frequently undermine their efforts to lose weight and keep it off. A cognitive therapy program that underscores the inextricable connection between emotions and eating, and how to manage that connection successfully using positive long-term mental strategies has been developed and found useful.  Self-monitoring with daily records of place and time of food intake, as well as accompanying thoughts and feelings, helps identify the physical and emotional settings in which eating occurs. Physical activity typically is recorded in minutes or calories expended. Self-monitoring also gives clues to the occurrence of relapses and consequent guilt and how they can be prevented.  A comprehensive program of lifestyle modification produces a loss of approximately 10% of initial weight in 16 to 26 weeks, as revealed by a review of recent randomized controlled trials (RCTs), including the Diabetes Prevention Program. Long-term weight control is facilitated by continued patient-therapist contact, whether provided in person or by telephone, mail, text messaging, or email. Multiple strategies for behavioral therapy often are needed. Dietary Modification Recommendations Weight loss programs with any degree of success integrate food choice changes with exercise, behavior modification, nutrition education, and psychologic support. When these approaches fail to bring about the desired reduction in body fat, medication may be added. For morbid obesity (BMI of 40 or greater), surgical intervention may be required. Weight loss programs should combine a nutritionally balanced dietary regimen with exercise and lifestyle modification. Treatment options depends on the goals and health risks of the patient include the following: A low calorie, macronutrient adjusted eating plan, increased physical activity, and lifestyle modification A low calorie macronutrient adjusted eating plan, increased physical activity, lifestyle modification, and pharmacotherapy Surgery plus an individually prescribed eating regimen, physical activity, and lifestyle modification program Prevention of weight regain through energy intake and output balance Mindset interventions Restricted-Energy Diets A balanced, restricted-energy diet is the most widely prescribed method of weight reduction. The diet should be nutritionally adequate except for energy, which is decreased to the point at which fat stores must be mobilized to meet daily energy needs. Regardless of the level of CR, healthful eating should be taught and recommendations for increasing physical activity should be included.  A caloric deficit of 500 to 1000 kcal daily usually meets this goal. The energy level varies with the individual’s size and activities, usually ranging from 1200 to 1800 kcal daily. The low-calorie diet should be individualized : for carbohydrates (50% to 55% of total kilocalories), using sources such as vegetables, fruits, beans, and whole grains. Generous protein, approximately 15% to 25% of kilocalories, is needed to prevent conversion of dietary protein to energy. Fat content should not exceed 30% of total calories. Extra fiber is recommended to reduce caloric density, to promote satiety by delaying stomach emptying time, and to decrease to a small degree the efficiency of intestinal absorption.  Calculating fat as a percentage of calories is useful. A simple rule is to divide ideal calorie level by 4 for a 25% fat intake (e.g.,an 1800-kcal intake needs 450 kcal from fat, or, at approximately 9 kcal/g, approximately 50 g of fat). Giving the person the option to distribute fat grams throughout the day makes the approach more appealing, involves the person in the process, and decreases energy intake without hunger. Total calories also must be considered.  Vitamin and mineral supplements that meet age-related requirements usually are recommended when there is a daily intake of less than 1200 kcal for women, less than 1800 kcal for men, or when it is difficult to choose foods that will meet all nutrient needs at the restricted energy intake.  Alcohol and foods high in sugar should be limited to small amounts for palatability. Alcohol makes up 10% of the diet for many regular drinkers and contributes 7 kcal/g. Heavy drinkers who consume 50% or more of daily calories from alcohol may have a depressed appetite, whereas moderate users tend to gain weight with the added alcohol calories. Habitual use of alcohol may result in lipid storage, weight gain, or obesity Formula Diets and Meal Replacement Programs Formula diets are commercially prepared, ready-to-use, portion controlled meal replacements. These meal replacements - drinks, prepackaged meals or entrees, or meal bars - can be found over the counter (OTC) in drug stores, supermarkets, and franchised weight loss centers, or in a clinical setting. The goal with use of these foods is to provide structure and replace other higher calorie foods. Per serving, most meal replacements include 10 to 20 g of protein, various amounts of carbohydrate, 0 to 10 g of fat, up to 5 g of fiber, and 25% to 30% of recommended dietary allowances for vitamins and minerals. Usually drinks or shakes are milk (casein or whey), pea protein, rice protein, or soy based, are high in calcium, and have 150 to 250 kcal per 8 oz. They are frequently ready to use, portion controlled, or are made with a purchased powder. Extreme Energy Restriction and Fasting Extreme energy-restricted diets provide fewer than 800 kcal per day, and starvation or fasting diets provide fewer than 200 kcal per day. Fasting is seldom prescribed as a treatment; however, it frequently is invoked as a part of religious or protest regimen or in a personal effort to lose weight. Under these circumstances it is seldom continued long enough to produce the serious neurologic, hormonal, and other side effects that accompany prolonged starvation.  More than 50% of the rapid weight reduction is fluid, which often leads to serious hypotension. Accumulation of uric acid can precipitate episodes of gout; gallstones also can occur. Also, as fat stores diminish, molecules are released that can affect further weight loss. Sometimes what starts as extreme energy restriction to lose weight leads to more disordered eating patterns.  Very Low–Calorie Diets Diets providing 200 to 800 kcal are classified as very low–calorie diets (VLCDs). Little evidence suggests that an intake of fewer than 800 calories daily is of any advantage. Even though there are significantly greater weight losses with VLCDs in the short term, there are no significant differences in the weight losses in the long term. For some case as hospitalized patient rapid weight loss is considered.  Most VLCDs are hypocaloric, but relatively rich in protein (0.8 to 1.5 g/kg IBW per day). They are designed to include a full complement of vitamins, minerals, electrolytes, and essential fatty acids, but not calories, and they are usually given for a period of 12 to 16 weeks. Their major advantage is rapid weight loss. Because of potential side effects, prescription of these diets is reserved for persons with a BMI of more than 30 for whom other diet programs with psychotherapy have been unsuccessful. Occasionally VLCDs may be indicated for persons with a BMI of 27 to 30 who have one or more comorbidities, or other risk factors.  VLCDs can lead to an increase of urinary ketones that interfere with the renal clearance of uric acid, resulting in increased serum uric acid levels or gout. Higher serum cholesterol levels resulting from mobilization of adipose stores pose a risk of gallstones. Additional adverse reactions include cold intolerance, fatigue, lightheadedness, nervousness, euphoria, constipation or diarrhea, dry skin, anemia, and menstrual irregularities; some of these are related to triiodothyronine (thyroid) deficiency Popular Diets!  Results of U.S. Department of Agriculture Scientific Review of Popular Diets Physical Activity Physical activity is the most variable component of energy expenditure. By increasing LBM in proportion to fat, physical activity helps to balance the loss of LBM and reduction of RMR that inevitably accompany intentional weight reduction. Other positive side effects of increased activity include strengthening cardiovascular integrity, increasing sensitivity to insulin, and expending additional energy and therefore calories.  Adequate levels of physical activity appear to be 60 to 90 minutes daily, as recommended by the USDA. Overweight and obese adults should gradually increase to these levels of physical activity. There is evidence that, even if an overweight or obese adult is unable to achieve this level of activity, significant health benefits can be realized by participating in at least 30 minutes of daily activity of moderate intensity.  Aerobic and resistance training should be recommended. Resistance training increases LBM, adding to the RMR and the ability to use more of the energy intake, and it increases bone mineral density, especially for women. Aerobic exercise is important for cardiovascular health through elevated RMR, calorie expenditure, energy deficit, and loss of fat. In addition to the physiologic benefits of exercise are relief of boredom, increased sense of control, and improved sense of well-being.  The recommendations for exercise from the American College of Sports Medicine differ for weight loss vs weight maintenance. Physical activity 150 minutes/week has a minimal effect on weight loss. Physical activity 150 minutes/week usually results in modest weight loss (defined as ,2-3 kg), with physical activity between 225 and 420 minutes/week resulting in the greatest weight loss (5 to 7.5 kg). While research on maintaining weight indicates that moderately vigorous physical activity of 150 to 250 minutes per week at an energy equivalent of ,1200 to 2,000 kilocalories per week (about 12 to 20 miles per week of jogging or running) is sufficient to prevent weight gain. Pharmaceutical Management Appropriate pharmacotherapy can augment diet, physical activity, and behavior therapy as treatment for patients with a BMI of 30 or higher or patients with 27 or higher who also have significant risk factors or disease. These agents can decrease appetite, reduce absorption of fat, or increase energy expenditure. As with any drug treatment, physician monitoring for efficacy and safety is necessary. Food and Drug Administration (FDA)–approved pharmacotherapy Medications currently available can be categorized as central nervous system (CNS) acting agents and non–CNS-acting agents.  The CNS-acting agents fall into the categories of catecholaminergic agents, serotoninergic agents, and combination catecholaminergic- serotoninergic agents. Common side effects of CNS-acting agents are dry mouth, headache, insomnia, and constipation.  As of April, 2015, five long-term weight loss drugs were listed as approved by the FDA (FDA, 2015). They are: orlistat (Xenical), locaserin (Beliviq), phentermine topiramate (Qysmia), naltrexone-buproprion (Contrav), and liragluide (Saxenda) Orlistat The mode of action of the weight loss drug orlistat is unusual in that it inhibits gastrointestinal lipase, which reduces approximately one third the amount of fat that is absorbed from food. Depending on the fat content of a person’s diet, this lowered absorption can represent 150 to 200 kcal/day. With lowered fat-soluble vitamin absorption, supplements typically are recommended, separated from the drug dosage by 2 hours or more. A weight loss of 3 to 5 kg in orlistat-treated patients is common. Side effects are gastrointestinal: oily spotting, fecal urgency, and flatus with discharge. Health benefits include reduced low density lipoprotein (LDL) cholesterol and elevated HDL cholesterol, improved glycemic control, and reduced blood pressure. Orlistat (Xenical or Alli ) Note: Rare cases of severe liver injury reported. Should not be taken with cyclosporine. Bariatric Surgery Bariatric surgery is at this point considered the only long term effective treatment for extreme or class III obesity with a BMI of 40 or greater, or a BMI of 35 or greater with comorbidities. Gastroplasty or stomach restricting procedures, decrease the amount of food entering the gastrointestinal tract. Other surgical procedures, such as Roux-en-Y, are restrictive and cause malabsorption because they also prevent food from being absorbed from the gastrointestinal tract.  Before any extremely obese person is considered for surgery, failure of a comprehensive program that includes CR, exercise, lifestyle modification, psychologic counseling, and family involvement must be demonstrated. Failure is defined as an inability of the patient to reduce body weight by one third and body fat by one half, and an inability to maintain any weight loss achieved. Such patients have intractable morbid obesity and should be considered for surgery.  If surgery is chosen, the patient is evaluated extensivelywith respect to physiologic and medical complications, psychologic problems such as depression or poor self-esteem, and motivation. Counseling sharply improves the outcomes for dieting and drug therapy in this population. Postoperative follow-up requires evaluation at regular intervals by the surgical team and a registered dietitian nutritionist (RDN). In addition, behavioral or psychologic support is necessary. Studies indicate some positive physiologic changes in liver fibrosis, BMI, branched chain amino acid production and reversal of insulin-induced increases in brain glucose metabolism.  Gastric Bypass, Gastroplasty, Gastric Banding, and the Sleeve Gastrectomy  Gastroplasty and gastric bypass procedures reduce the amount of food that can be eaten at one time and produce early satiety The new stomach capacity may be as small as 30 ml or approximately 2 tablespoons. After surgery the patient’s diet progresses from clear liquid, to full liquid, to puree, soft, and finally to a regular diet as tolerated, with emphasis on protein intake.  Gastroplasty with gastric banding Patients who undergo the banding procedures usually do not require folic acid, iron, or vitamin B12 replacements, but nutritional status monitoring on a regular basis is still recommended.  Gastric bypass - the Roux-en-Y gastric bypass (RYGB) Because use of the lower part of the stomach is omitted, the gastric bypass patient may have dumping syndrome as food empties quickly into the duodenum.  The tachycardia, sweating, and abdominal pain are so uncomfortable that they motivate the patient to make the appropriate behavioral changes and refrain from overeating. However, patients tend to choose liquids and weight loss can then be deterred by drinking too much calorically dense liquid like milk shakes and soft drinks. Eventually the pouch expands to accommodate 4 to 5 oz at a time. Frequently, gastric bypass surgery leads to bloating of the pouch, nausea, and vomiting. A postsurgical food record noting the tolerance for specific foods in particular amounts helps in devising a program to avoid these episodes.  Up to 16% of patients may experience postoperative complications. These include anastomotic leaks, strictures, perforation, gastric fistulas, bowel obstructions, wound infections, respiratory failure and intractable nausea and vomiting. Additionally, bypass surgery places an individual at high risk for malnutrition that requires lifelong follow-up and monitoring by the multidisciplinary team. Nutritional status should be frequently evaluated by an RDN.  Monitoring should include an assessment of total body fat loss, potential anemia, and deficiencies of potassium, magnesium, folate, and vitamin B12. Ice-cube pica and iron deficiency anemia are possible. Supplementation is necessary. An adult vitamin-mineral supplement (one liquid or chewable tablet twice daily) containing 1200 to 1500 mg calcium citrate, 400 to 2000 IU vitamin D, 500 mcg vitamin B12, 400 mg folic acid, and 65 to 80 mg elemental iron with vitamin C is suggested.  The laparoscopic sleeve gastrectomy (LSG) initially was used for patients with a BMI greater than 60 as a precursor to RYGB, but it is now used as a stand-alone procedure and currently is the most popular bariatric surgery in the U.S. A sleeve is created by cutting the antrum of the stomach away from the pylorus and forming a pouch around a bougie on the side of the lesser curvature of the stomach. This reduces the stomach capacity by about 80% through the removal of the fundus and body.  Complications associated with the LSG can include gastric bleeding, stenosis, leak, and reflux. After resection, the greater curvature of the stomach can bleed. Treatment involves transfusion and possibly an additional laparoscopy to reinforce the bleeding area with sutures. Each case requires the surgeon’s expertise to decide if a patient can resume oral intake, will need nutrition support such as enteral feedings through a jejunostomy tube, or may require parenteral nutrition. Occasionally, RYGB is necessary to resolve reflux complications. COMMON PROBLEMS IN OBESITY TREATMENT The prognosis for maintaining reduced body weight is typically poor. Continued dieting, with repeated ups and downs, leads gradually to a net increase in body fat and thus to a health risk for hyperlipidemia, hypertension, diabetes, and even osteoarthritis. Maintaining Reduced Body Weight Energy requirements for weight maintenance after weight reduction appear to be 25% lower than at the original weight. The net effect is that reduced-obese persons are faced with the necessity of maintaining a reduced energy intake, even after the desired weight has been lost. Whether this reduced intake must be maintained indefinitely is not known. 5000 individuals who have been successful in long-term weight loss maintenance report the following: 1. Eating a relatively low-fat (24%) diet 2. Eating breakfast almost every day 3. Weighing themselves regularly, usually once per day to once per week 4. Engaging in high levels (60 to 90 minutes per day) of physical activity Some phrasescan be shared with individuals who are trying to maintain their weight loss, including the following: l. The best diet is “don’t buy it.” 2. “Easy does it”—use moderation at all meals. 3. “Don’t drink your calories.” 4. Keep the “extras” to no more than 200 kcal per day. Plateau Effect A common experience for the person in a weight reduction program is arrival at a weight plateau, when weight remains at the same level for a long period. Eventually weight loss halts completely.  One theory is that interim plateaus reflect a reduction of lipid in individual adipocytes to some level that signals metabolic adjustment and weight maintenance. Another theory is that there is a release of toxins from adipose tissue that acts as an endocrine disruptor and inflammatory agent and affects subsequent weight loss.  To move out of this phase usually requires an increase in activity level or a change in food choices to include more fruits and vegetables which are naturally higher in detoxifying phytochemicals.  The fact that RMR decreases rapidly at the onset of a weight reduction diet, by as much as 15% within 2 weeks, indicates that other adaptations to the lower weight and the threat of deprivation are taking place. A decrease in the total kilocalories ingested results in a decrease in total energy expenditure. Because a body that weighs less requires less energy expenditure to move around, the cost of physical activity is also less.  A state of equilibrium eventually is reached at which the energy intake is equal to energy expenditure. Unless a change is made in either nutritional intake or physical activity, weight loss stops at this point. Weight Cycling Repeated bouts of weight loss and regain, known as weight cycling or the yo-yo effect, occurs in men and women and is common in overweight and normal weight individuals. The effect of weight cycling appears to result in increased body fatness and weight, with the end of each cycle.  WEIGHT IMBALANCE: EXCESSIVE LEANNESS OR UNINTENTIONAL WEIGHT LOSS & Weight Gain Therapy