Weight Management Chapter 9

Overweight and Obesity Major health problem in the United States Growing concern worldwide Prevalence continues to increase Women, poor, blacks, and Mexican Americans Children BMI of 25 or greater Global food system Abundant energy-dense, processed, affordable products

Increasing Prevalence of Obesity Among US Adults Figure 9-1 Increasing prevalence of obesity among U.S. adults

Fat Cell Development When energy in exceeds energy out: Adipose tissue fat cells store excess Number and size of body fat cells Fat cell numbers increase during childhood and adolescence Cell proliferation When energy out exceeds energy in: Fat cell size decreases No change in number

Fat Cell Development Illustrated Figure 9-2 Fat cell development

During growth, fat cells increase in number. When energy intake exceeds expenditure, fat cells increase in size. When fat cells have enlarged and energy intake continues to exceed energy expenditure, fat cells increase in number again. With fat loss, the size of the fat cells shrinks but not the number. Figure 9-2 Fat Cell Development Fat cells are capable of increasing their size by 20-fold and their number by several thousand fold. Stepped Art

Fat Cell Metabolism Lipoprotein lipase (LPL) activity Storage of triglycerides Differences between obese and lean people Activity in varying body regions Differences between men and women Gender differences in enzyme activity Releasing and breaking down fat Fat oxidation not efficient Set point theory

Genetics and Epigenetics Causative role of genetics Multiple genetic influences Genetics may determine susceptibility to obesity Genes interact with: Diet and physical activity Metabolic pathways Human genome

Obesity Gene Gene named ob Codes for the protein leptin Acts as a hormone in hypothalamus Promotes negative energy balance Suppresses appetite Increases energy expenditure Leptin injections effective in reducing body weight in animals and humans With genetic deficiency of leptin or receptor mutation

Mice With and Without Leptin Compared Figure 9-3 Mice with and without leptin compared

Ghrelin Secreted by the stomach cells Increases appetite Promotes positive energy balance Inverse correlation with body weight Psychological mindset influences ghrelin’s response to a meal Mindset of indulgence promotes satiety Promotes sleep

Uncoupling Proteins Types of body fat White adipose tissue Stores fat for use by other cells Oxidation releases energy as ATP and heat Brown adipose tissue Releases stored energy as heat Oxidation uncoupled from ATP formation Differences in brown fat between obese and normal weight people

Brite Adipocytes Some white fat can undergo browning process Takes on characteristics of brown fat Resulting cells called brite adipocytes More abundant than brown fat cells in adults Physical activity can trigger the process

Environment Obesity reflects interaction between genes and the environment Overeating Present and past eating and activity patterns influence current body weight Food availability Serving sizes Restaurant food

Physical Inactivity Life requires little exertion Modern conveniences Inactivity contributes to weight gain and poor health Sedentary activities and weight gain DRI for prevention of weight gain 60 minutes of moderately intense activity daily

Health Risks Risk indicators Beneficial weight loss BMI Waist circumference Disease risk profile Factors taken into account Beneficial weight loss Health status Motivation

Different Conditions Overweight in good health Sometimes health is not the motivation for weight loss Obese or overweight with risk factors Weight loss recommended with two or more risk factors Obese or overweight with life-threatening condition Weight loss recommended

Perceptions and Prejudices Most obese people do not successfully lose weight and maintain the loss Social consequences Jobs, school, and social situations People judged by appearance Psychological problems Embarrassment Other feelings

The Psychology of Weight Cycling Figure 9-4 The psychology of weight cycling

Stepped Art – Weight Cycling I am fat and unhappy. I lose a little weight, but then regain it (and sometimes more). I want to be happy. Figure 9-4 The psychology of weight cycling If I lose weight, I will be happy. I try too hard to reach an unrealistic goal. Stepped Art – Weight Cycling

Dangerous Interventions Diet books and weight-loss programs Little success maintaining weight loss Fad diets Weight-loss products Herbal products Laws for dietary supplements Other gimmicks

Drug Treatment for Obesity Strategies for weight reduction depend on: Degree of obesity Risk of disease Use drugs as part of long-term comprehensive weight-loss program For people with medical risks Assist with modest weight loss FDA approval Mandate: benefits must outweigh risks

FDA-Approved Drugs for Weight Loss Action Side Effects Orlistat (OR-leh-stat), trade names: Alli, Xenical Inhibits pancreatic lipase activity in the GI tract, thus blocking digestion and absorption of dietary fat and limiting energy intake Gl cramping, diarrhea, gas, frequent bowel movements, reduced absorption of fat-soluble vitamins; rare cases of liver injury Phentermine (FEN-ter- mean), diethylpropion (DYE-eth- ill-PRO-pee-on). phendimetrazine (FEN-dye-MEH-tra-zeen) Enhances the release of the neurotransmitter norepinephrine, which suppresses appetite Increased blood pressure and heart rate, insomnia, nervousness, dizziness, headache Lorcaserin hydrochloride, trade name: Belviq (BELL-veek) Interacts with brain serotonin receptors to increase satiety and reduce food intake Headache, dizziness, fatigue, nausea, dry mouth, and constipation; low blood glucose in people with diabetes; serotonin syndrome, including agitation, confusion, fever, loss of coordination, rapid or irregular heart rate, shivering, seizures, and unconsciousness; cannot be safely used by pregnant or lactating women or people with heart-valve problems; high doses cause hallucinations Phentermine (an appetite suppressant) and topiramate (a seizure/migraine medication) combination, trade name: Qsymia (kyoo-sim-EE-uh) Enhances the release of the neurotransmitter norepinephrine, which suppresses appetite, and increases the feeling of being full, making foods taste less appealing Increased heart rate; can cause birth detects if taken in the first weeks or months of pregnancy; increased heart rate; suicidal thoughts; may worsen glaucoma and other eye problems Table 9-1 FDA-approved drugs for weight loss NOTE: Weight-loss drugs are most effective when taken as directed and used in combination with reduced-kcalorie diet and increased physical activity

Surgical Treatments for Obesity Clinically severe obesity (BMI > 40) More than 100,000 surgeries performed annually in the United States Reduces food capacity of stomach Effectively limits food intake Gastric bypass changes hormone production Health benefits Long-term safety and effectiveness Liposuction

Gastric Surgery Used in the Treatment of Severe Obesity Figure 9-5 Gastric surgery used in the treatment of severe obesity

Weight Loss Strategies Characteristics of successful strategies Embrace changes Celebrate losses Set goals Psychosocial support Benefits of modest weight loss Reasonable weight loss rate: 0.5 to 2 lb. per week Incorporation of healthy eating and physical activity

Eating Patterns, Part 1 Be realistic about energy intake Provide less energy than needed Avoid restrictive eating Avoid rapid weight loss Goal: nutritional adequacy without excess Deficit of 500 to 1000 kcalories per day Breakfast frequency Inversely related to obesity

Eating to Lose Weight Nutritional adequacy Eat small portions Minimum 1200 kcalories per day Eat small portions Eat less food at each meal Feel satisfied, not stuffed Prepared meal plans Slow down Reduce energy density Remember water

Energy Density Decreasing the energy density (kcal/g) of foods allows a person to eat satisfying portions while still reducing energy intake. To lower energy density, select foods high in water or fiber and low in fat. By selecting the water-packed tuna (on the right) instead of the oil-packed tuna (on the left), a person can enjoy the same amount for fewer kcalories. Selecting grapes with their high water content instead of raisins increases the volume and cuts the energy intake. Even at the same weight and similar serving sizes, the fiber-rich broccoli delivers twice the fiber for about one-third the energy. Figure 9-6 Energy density

Eating Patterns, Part 2 Focus on fiber Choose fats sensibly Low in energy and high in nutrients Requires effort to eat Choose fats sensibly Energy density and satiation Select carbohydrates carefully Artificial sweeteners Watch for empty kcalories Fat, sugar, and alcohol

Weight-Loss Strategies Food Activities To maintain weight, consume foods and drinks to meet, not exceed, kcalorie needs. To lose weight, energy out should exceed energy in by about 500 kcalories/day. Emphasize foods with a low energy density and a high nutrient density; make legumes, whole grains, vegetables, and fruits central to your diet plan. Eat slowly. Drink water before you eat and while you eat; drink plenty of water throughout the day. Track food and kcalorie intake. Plan ahead to make better food choices. Limit kcalorie intake from solid fats and added sugars. Reduce portions, especially of high- kcalorie foods. Cook and eat more meals at home, instead of eating out. When eating out, think about choosing healthy options. Limit screen time. Increase physical activity. Choose moderate- or vigorous-intensity physical activities. Avoid inactivity. Some physical activity is better than none. Slowly build up the amount of physical activity you choose. Table 9-3 Weight loss strategies

Physical Activity Best approach to weight management Moderate physical activity plus activities of daily life Combination of diet and physical activity Lose more fat Retain more muscle Regain less weight Reduction of abdominal fat

Activity Energy Expenditure kCalorie expenditure Influenced by body weight, intensity, and duration Greater the energy deficit, greater the fat loss Discretionary kcalorie allowance Metabolism Speeds up with activity Immediate and long-term benefits

Influence of Physical Activity on Discretionary kCalories Figure 9-7 Influence of physical activity on discretionary kcalories

Physical Benefits of Activity Body composition Fat decreases and lean body mass increases Strength-training exercises Abdominal fat Appetite control Delayed appetite Inappropriate appetite

Psychological Benefits of Activity Self-esteem Choosing activities Ones you enjoy and are willing to do regularly Moderate intensity 2000 kcalories per week Energy-expending daily activities Spot reducing

Environmental Influences Factors surrounding eating experience and the food itself Changes can influence amount a person eats Atmosphere Pleasant and comfortable equals more food Accessibility Less effort needed to obtain food, more food eaten

Environmental Factors While Eating Socializing Duration of meal Visual cues Distraction Distractions Initiating eating Interfering with internal controls Extending duration of eating

Other Environmental Factors That Influence Eating Multiple choices Large assortments of foods increase consumption Package and portion sizes Serving containers

Behavior and Attitude Behavior modification Become aware of behaviors Positive, matter-of-fact attitude Become aware of behaviors Keep record Change behaviors Set small, time-specific goals Practice Reward

Cognitive Skills Problem solving Cognitive restructuring Replace negative thoughts Personal attitude Understand personal relationship with food Sound emotional health Support groups

Successful Weight Loss Maintained for at least a year Prevalence of successful weight loss Difficult to determine Components of successful weight loss Vigorous exercise regimens Careful eating patterns Frequent self-monitoring

Maintaining Weight Loss Hormonal and metabolic changes Persist over time Takes more effort to prevent weight regain than to prevent weight gain

Prevention Preventing weight gain Form beneficial habits Easier than losing weight Strategies similar to losing weight Start earlier Form beneficial habits Food choices Activity

Community Programs Reversing obesity epidemic in the United States Challenging May require community action to promote healthy lifestyle choices Efforts go beyond individuals Social networks Community institutions Government policies

National Strategies to Prevent Obesity • Provide a variety of opportunities to help make physical activity an integral and routine part of life. • Create environments that ensure healthy foods and beverages are visible, attractive, and easy-to-obtain. • Encourage media messages that promote physically active lifestyles and nutritionally healthy diets. • Support health care providers in offering information on weight management and employers in offering wellness programs. • Make schools centers for health and wellness. SOURCE: Accelerating Progress in Obesity Prevention: Solving the Weight of the Nation, (Washington. DC: Institute of Medicine of the National Academies). 2012. Table 9-4 National strategies to prevent obesity

Underweight Affects fewer than two percent of U.S. adults Weight gain a matter of health Individual matter Weight gain may be difficult Physical conditioning combined with high energy intakes

Problems of Underweight Diverse causes High demand for energy may contribute Physical activity Growth and development Difficult to gain weight Adaptive thermogenesis Learn new habits and like new foods Difference between underweight and anorexia nervosa

Weight-Gain Strategies Key diet planning strategies Adequacy and balance Energy-dense foods Regular meals daily Large portions Extra snacks Juice and milk Liquid supplements for illness Exercise to build muscles

The Latest and Greatest Weight-Loss Diet – Again Highlight 9

Fad Diets Outrageous claims Numerous fad diet plans No requirements to prove the claims Do not have to undertake credible research Often distorted research Anyone can publish anything Numerous fad diet plans

Fad Diets’ Appeal Market for weight-loss products is huge Estimated $33 billion yearly in United States Greatest appeal Tend to ignore sound dietary recommendations Sophisticated and often erroneous explanations Tend to work for short time Fail to produce long-lasting results

Don’t Count kCalories Claim to disregard kcalories Follow a plan Designed to have low energy intake Tend to lack variety Monotonous Often recommend dietary supplement Follow a plan Most fad diets cannot support optimal health over time

The Real Deal Fad diet “magical powers” Weight loss Tipping the energy balance equation to greater energy expenditure Weight loss Long-term lifestyle changes Healthy plan Flexibility and variety