5 Weight Management Cengage Learning 2015 Weight Management

5 Weight Management © Cengage Learning 2015

Weight Management • Obesity is a body mass index (BMI) of 30 or higher, when excess body fat can lead to serious health problems • An estimated 35% of the adult population in industrialized nations is obese • The average weight of American adults has increased by 25 pounds or more since 1965 • The prevalence of obesity is higher in African Americans and Hispanic Americans © Cengage Learning 2015

Overweight and Obese in the US © Cengage Learning 2015

Weight Management (cont’d. ) • Excessive body weight combined with physical inactivity is the second leading cause of preventable death in the United States • Obesity and unhealthy lifestyle habits are the most critical public health problems we face in the 21 st century © Cengage Learning 2015

Overweight versus Obesity • Overweight and obese are not the same thing • Obesity results in: – Decrease in life expectancy – Decrease in quality of life – Increase in illness and disability © Cengage Learning 2015

Overweight versus Obesity (cont’d. ) • A primary objective to achieve overall physical fitness and enhanced quality of life is to attain recommended body composition • Being underweight is also a problem that can lead to many medical disorders and death – about 14% of people in the US are underweight © Cengage Learning 2015

Tolerable Weight • When people set their own target weight, they should be realistic • “Ideal” body shapes illustrated in popular magazines are achieved mainly through airbrushing and medical reconstruction • Failure to attain a “perfect body” may lead to eating disorders in some individuals © Cengage Learning 2015

The Weight Loss Dilemma • Frequent fluctuations in weight (yo-yo dieting) markedly increase the risk for dying from cardiovascular disease • Quick-fix diets should be replaced by a slow but permanent weight-loss program © Cengage Learning 2015

The Weight Loss Dilemma (cont’d. ) • Diet without exercise – Only ~10% of people who begin program are able to lose desired weight – Only ~5% are able to keep it off • Traditional diets fail because few of them incorporate permanent behavioral changes © Cengage Learning 2015

Self-Reported versus Actual Caloric Intake and Exercise © Cengage Learning 2015

Diet Crazes • Fad diets deceive people and claim that dieters will lose weight by following all instructions – With diets that are very low in calories, a lot of the weight loss is water and protein, not fat – Dropout rates are high because of difficulty adhering to limited dietary plans – Popular diets: DASH, Volumetrics, Best Life, Weight Watchers, Ornish, Zone, Atkins, South Beach, Glycemic Index Diet, Biggest Loser, Mediterranean © Cengage Learning 2015

Crash Diets • Less than 800 calories/day – Glycogen storage is depleted in a few days – Half the weight loss is lean (protein) tissue, including heart muscle – Increases risk of heart attacks or fatal cardiac arrhythmias – Sodium depletion may cause a dangerous drop in blood pressure © Cengage Learning 2015

Low-Carb Diets • Low-carbohydrate/high-protein (LCHP) diets – Eat all the protein foods you want – Limited fruits and vegetables – High in fat – Low glycemic index; slows insulin response • Rapid weight loss due to loss of lean tissue and body water; effectiveness dwindles over time • Increases the risk for heart disease, cancer, and kidney or bone damage © Cengage Learning 2015

Key Terms • Glycogen – Manner in which carbohydrates (glucose molecules) are stored in the human body, predominantly in the liver and muscles. • Glycemic index – Used to rate the plasma glucose response of carbohydrate-containing foods with the response produced by the same amount of a standard carbohydrate, usually glucose or white bread © Cengage Learning 2015

Effects of High- and Low-Glycemic Intake on Blood Glucose Levels © Cengage Learning 2015

Eating Disorders • Eating disorders are medical illnesses characterized by intense fear of becoming fat – thought to stem from environmental pressures – Anorexia nervosa: self-imposed starvation Bulimia nervosa: pattern of binge eating and purging – Binge-eating disorder: uncontrollable episodes of eating excessive amounts of food within a relatively short time – Emotional eating: consumption of large quantities of food to suppress negative emotions © Cengage Learning 2015

Eating Disorders (cont’d. ) • Most prevalent in women 25 to 50 • Often a coping mechanism to avoid dealing with family and social problems – Clinical depression – Obsessive-compulsive behavior – Chemical dependency – Victims of sexual molestation © Cengage Learning 2015

Eating Disorders (cont’d. ) • Eating disorders develop in stages: – Start with weight loss diet – Dieting becomes extreme – Often combined with exhaustive exercise and overuse of laxatives and diuretics – Becomes the primary focus of attention © Cengage Learning 2015

Anorexia Nervosa • • Fear of weight gain is greater than fear of death Distorted image of body Preoccupation with food/meal planning Diagnostic criteria: – Refusal to maintain body weight – Intense fear of gaining weight or becoming fat – Altered perception of body weight, size, or shape – Amenorrhea • Treatment requires professional help © Cengage Learning 2015

Bulimia Nervosa • More prevalent than anorexia nervosa – Mostly well-educated, near recommended weight, emotionally insecure, lacking self-esteem • Binge-purge cycle – Anticipation of cycle – Urgency to begin binging – Eating large and uncontrollable amounts – Short period of satisfaction – Feelings of guilt, shame, and fear – Purging © Cengage Learning 2015

Bulimia Nervosa (cont’d. ) • Diagnostic criteria: – Recurrent episodes of binge eating – Self-induced vomiting; misuse of laxatives, diuretics, other medications, or enemas; fasting; or excessive exercise – Binging and compensatory behaviors both occur at least twice a week for three months – Undue importance of body shape and weight © Cengage Learning 2015

Binge-Eating Disorder • Causes are unknown; triggered by depression, anger, sadness, boredom • Do not purge; may be overweight or obese • Diagnostic criteria: – Eating an unusually large amount of food – Eating until uncomfortably full – Eating out of control; faster than usual – Eating alone because of embarrassment – Feeling disgusted, depressed, or guilty © Cengage Learning 2015

Emotional Eating • Emotional eating involves consumption of large quantities of “comfort” and junk food to suppress negative emotions • Foods such as chocolate cause the body to release mood-elevating opiates, helping to offset negative emotions © Cengage Learning 2015

Dealing with Emotional Eating • Differentiate between emotional and physical hunger • Avoid unhealthy foods • Keep healthy snacks handy • Use countering techniques • Keep a “trigger log” • Work it out with exercise instead of food © Cengage Learning 2015

Treatment • Treatment for eating disorders is available through school counseling or health centers and local hospitals • Many communities have support groups led by professional personnel © Cengage Learning 2015

Physiology of Weight Loss • Three assumptions: – Balancing food intake against output allows a person to achieve recommended weight – All fat people simply eat too much – The human body doesn’t care how much (or little) fat it stores • Obesity involves a combination of genetics, behavior, and lifestyle factors © Cengage Learning 2015

Energy-Balancing Equation • Energy-balancing equation – As long as caloric input equals caloric output, a person will not gain or lose weight – If caloric intake exceeds output, the person gains weight – When output exceeds input, the person loses weight • Estimated energy requirement (EER): average energy (caloric) intake that is predicted to maintain energy balance for a specific person © Cengage Learning 2015

Energy-Balancing Equation (cont’d. ) • Three components of total daily energy requirement: – Resting metabolic rate (energy required to maintain vital body processes in resting state) – Thermic effect of food – Physical activity © Cengage Learning 2015

Components of Total Daily Energy Requirement © Cengage Learning 2015

Energy-Balancing Equation (cont’d. ) • One pound of fat = 3, 500 calories • Two people with similar measured caloric intake and output seldom lose weight at the same rate • Several theories might explain these individual variations © Cengage Learning 2015

Setpoint Theory • A weight-regulating mechanism (WRM) in the human body has a setpoint for controlling both appetite and the amount of fat stored – Every person has his or her own body fat percentage that the body attempts to maintain – Under calorie reduction, the body make metabolic adjustments to maintain its setpoint – The basal metabolic rate (BMR) may drop dramatically under a consistent negative caloric balance, and weight loss may plateau © Cengage Learning 2015

Key Terms • Weight-regulating mechanism (WRM) – The hypothalamus of the brain controls how much the body should weigh • Setpoint – Weight control theory that the body has an established weight and strongly attempts to maintain that weight © Cengage Learning 2015

Key Terms • Basal metabolic rate (BMR) – The lowest level of oxygen consumption necessary to sustain life • Very-low-calorie diet – Diet that allows an energy intake of only 800 calories or less per day © Cengage Learning 2015

Recommendation • Daily caloric intake of about 1, 500 calories, distributed properly over the basic food groups • Keep track of nutrients and calories consumed • Combine a sensible calorie-restricted diet with an increase in daily physical activity © Cengage Learning 2015

Lowering the Setpoint • Factors that affect the setpoint directly by lowering the fat thermostat: – Exercise – Diet high in complex carbohydrates – Nicotine – Amphetamines • The last two are more destructive than the extra fat weight © Cengage Learning 2015

Diet and Metabolism • When dieters lose weight by dietary restrictions alone, they lose lean body mass – weakens the organs and muscles and slows metabolism • When diet is combined with exercise, almost 100% of weight loss is fat, and lean tissue actually may increase © Cengage Learning 2015

Diet and Metabolism (cont’d. ) • Being sedentary is the main cause of lower metabolic rate, not aging • Basal metabolism is related to lean body weight • Severe caloric restrictions always prompts the loss of lean tissue © Cengage Learning 2015

Diet and Fat Loss © Cengage Learning 2015

Regulation of Appetite • Ghrelin, produced primarily in the stomach, stimulates appetite • Leptin, produced by fat cells, lets the brain know when you are full – Lack of physical activity leads to leptin resistance, leading to excessive eating • Sleep deprivation elevates ghrelin levels and decreases leptin levels, potentially leading to weight gain or keeping you from losing weight © Cengage Learning 2015

Monitoring Body Weight • A critical component of weight management is to regularly monitor your body weight – Easier to make short-term changes to lose one or two pounds of weight than to make drastic long term changes to lose 10 or more pounds gained over several months or years © Cengage Learning 2015

Exercise and Weight Management • Physical inactivity may be the primary cause leading to excessive weight and obesity • How much exercise do we need? – For health benefits • 30 minutes five days per week – To prevent weight gain • 60 minutes daily – To maintain substantial weight loss • 90 minutes daily © Cengage Learning 2015

Exercise and Weight Management (cont’d. ) • A combination of aerobic and strength-training exercises works best for losing weight – Aerobic exercise is best to offset the setpoint – Strength training is critical in helping maintain and increase lean body mass • Exercise helps increase muscle tissue, connective tissue, blood volume, glycogen, enzymes and other structures within the cell • FTO gene: only partially responsible for weight; lifestyle choices more important © Cengage Learning 2015

The Role of Exercise Intensity and Duration • Compared with vigorous intensity, a greater proportion of calories burned during lightintensity exercise are derived from fat • Overall, you can burn twice as many calories during vigorous-intensity exercise and, subsequently, more fat as well © Cengage Learning 2015

Energy Expenditure at Different Intensity Levels © Cengage Learning 2015

Overweight and Fit Debate • Can a person be overweight and fit? – Studies show higher aerobic fitness = lower mortality rate regardless of overweight or not – However, debate rages based on the definition of fit • Most fitness professionals do not agree that a person can be fit and fat – There are more than 50 medical conditions related to excess weight © Cengage Learning 2015

Healthy Weight Gain • For “skinny” people, the only healthy way to gain weight is through exercise (strength-training) and a slight increase in caloric intake • Higher caloric intake must be accompanied by a strength-training program; otherwise, the increase in body weight will be in the form of fat, not muscle tissue © Cengage Learning 2015

Weight Loss Myths • Spot reducing – Fallacious theory proposing that exercising a specific body part will result in significant fat reduction in that area • Cellulite – These deposits are nothing but enlarged fat cells from excessive accumulation of body fat • Other quick-weight-loss myths: – Rubberized sweat suits, steam baths, and mechanical vibrators © Cengage Learning 2015

Losing Weight the Sound and Sensible Way • Don’t try to do too much too fast • Benefits of exercise for weight control • Sensible caloric reduction – Exception: those already eating too few calories • Make wise food choices – Think long-term benefits instead of instant gratification – Estimate daily energy requirement (EER) based on age, total body weight, and gender © Cengage Learning 2015

Estimated Energy Requirement (EER) © Cengage Learning 2015

Losing Weight the Sound and Sensible Way (cont’d. ) • Determine average of calories burned daily from exercise, total minutes exercised weekly, and daily average exercise time • Obtain the daily energy requirement, with exercise, needed to maintain body weight • Target caloric intake to lose weight: EER – current weight x 5 • This final caloric intake to lose weight should not be below 1, 500 daily calories for most people © Cengage Learning 2015

Losing Weight the Sound and Sensible Way (cont’d. ) • Successful diets: about 24% calories from fat, 56% from carbohydrates, and 20% from protein • Breakfast is a critical meal while on a weight-loss program – Consuming most of your daily calories in one meal may cause more calories to be stored as fat – Consuming most calories earlier in the day helps lose weight and manage atherosclerosis © Cengage Learning 2015

Monitoring Your Diet with Daily Food Logs • People who monitor daily caloric intake are more successful at weight loss than those who don’t • To lose weight, use the diet plan that most closely approximates your target caloric intake • Pay particular attention to food serving sizes, and read food labels carefully © Cengage Learning 2015

Low-Fat Entrees • Use commercially prepared low-fat frozen entrees for lunch and dinner meals • Look for entrees that provide about 300 calories and no more than six grams of fat • Or prepare a similar meal using 3 ounces (cooked) lean protein with additional vegetables, that will provide 300 calories and 6 grams of fat © Cengage Learning 2015

Protein Intake • Minimize loss of lean body mass and hunger pains with more protein • 1. 0 -1. 2 g of protein per kg of body weight per day • Look for fat-free or low-fat protein sources – Greek yogurt, eggs, lean meat, tofu, quinoa, beans © Cengage Learning 2015

Effect of Food Choices on Long-Term Weight Gain • Regardless of other lifestyle habits, individuals who consume unhealthy foods gain more weight, and those who make healthy food choices gain less weight • Weight gain is strongly associated with the consumption of potato chips, potatoes, sugarsweetened beverages, and red meats © Cengage Learning 2015

Behavior Modification and Adherence • If weight management is to become a priority, people must transform their behavior • Surround yourself with people who have the same goals as you do © Cengage Learning 2015

The Simple Truth • Weight management is a lifetime commitment – When taking part in a weight (fat) reduction program, people also have to decrease caloric intake moderately, be physically active, and modify unhealthy eating behaviors • Three common reasons for relapse – Stress-related factors – Social reasons – Self-enticing behaviors • Those who persist will reap the rewards © Cengage Learning 2015

Assess Yourself • Are you satisfied with your current body composition and quality of life? If not, are you willing to do something about it? • Do you understand the following concepts? – The health consequences of obesity – Fad diets, myths, and fallacies about weight – Eating disorders – Physiology of weight loss & setpoint theory – Behavior modification techniques that support adherence to healthy habits © Cengage Learning 2015