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Weight management. Chapter 4. Obesogenic Environment. Toxic food environment Toxic physical activity environment. Toxic food environment. There’s more energy (calories) per capita than ever before. Eating out is increasingly common. Portion sizes are exploding.
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Weight management Chapter 4
Obesogenic Environment • Toxic food environment • Toxic physical activity environment
Toxic food environment • There’s more energy (calories) per capita than ever before. • Eating out is increasingly common. • Portion sizes are exploding. • Advertising budgets of healthy food and eating campaigns are dwarfed by the food industry.
EATING OUT STATISTICS Americans: • Spent 19% of food dollars on restaurant food in 1958 but 41% in 2009 • Spend $222 Billion at restaurants and 118 billion on fast food a year. • Consume 1/3 of our calories outside the home • On average, eat out 4 to 10x a week • Spend $800 million a day on restaurant food • Certain parts of the USA have seen a 60% increase in new restaurants
Toxic physical activity environment • Time spent in front of a TV or computer screen is on the rise. • Non-motorized travel to work and school is declining. • Jobs are more sedentary, leading to a less active workforce.
Incidence has doubled since 1970’s 2/3 of American adults are now overweight or obese 1/3 are obese! Rates are higher for African Americans and Hispanics THE EPIDEMIC IS HERE!
Causes of Overweight • Genetics (accounts for 50%-90% of the variation in body fat) • Age • Lifestyle • Race or ethnicity • Socioeconomic status • Psychological factors (e.g., emotional eating)
Genetics and Obesity • Weight is under substantial genetic control • Accounts for ~1/3 of BMI variations • Genetic influences contribute to differences among individuals in resting metabolic rate, body fat distribution and weight gain in response to overfeeding • Some people are predisposed to be obese which is readily nourished by a high fat, low activity lifestyle
Environment- What happened?? • More calories • Bigger portions • Fast food • Physical inactivity • Increased technology • Passive entertainment • Socioeconomics (obesity and poverty high correlation) • Prenatal factors • Childhood development • Genetics • Social networks • Emotional influences
Prevalence of Overweight and Obesity based on Ethnic Background • 46% of Mexican females and 35% of males • 48.6% of black African-American females and 30.9% of males • 32.9% of white females 32.9% of males • Diabetes more common among minorities • Ideal bodyweight different based on culture
Regulation of Eating and Body Weight • Hunger versus appetite • Satiation versus satiety • Energy balance • Energy output: basal metabolism, physical activity, thermic effect of food, thermogenesis • Energy intake: fat, carbohydrate, protein, alcohol • Energy imbalance (positive versus negative)
Weight Gain Eating more Less Energy Expenditure Or Both = Weight gain, specifically adipose tissue
How does it Happen? Fat Cell Development • Lipids are stored in fat cells of adipose tissue. • The amount of fat that someone has involves the number of cells and the size of those cells • The number of cells increases fastest in growing children just before puberty. • The more obese the child, the faster the cells increase • Fat cells will also expand in size (hypertrophy). Fat droplets will fill the cell. • When they reach full size, they can also divide (hyperplasia)
Why is difficult to Maintain Healthy Weight if Previously Obese? • Obesity is directly related to amount and size of cells • With weight loss, cell size diminishes, but fat cell amounts do not decrease • Those with an average number of fat cells will be able to hold onto weight losses easier
What the Body Uses Energy For • Basal and resting metabolic rate (BMR) • BMR is the minimum amount of energy spent during a fasting state to keep the body performing basic bodily functions. • RMR is similar to BMR but measures the activity to keep the basic body functions going in a nonfasting, noncompletely rested state (10% >BMR). • Thermoregulation • Physical activity above resting levels(TEE) • Processing food/digestion (TEF)
The Influence of Exercise on RMR RMR, TEF and TEE • TEF 10% of daily caloric expenditure • Exercise (TEE) is the most variable • in sedentary individuals 15% • May be 35% in some active individuals • RMR stays elevated after exercise • the higher the intensity of the exercise the higher RMR after exercise • Low intensity does not have this effect
Exercise, Dieting and RMR • Closely related to Fat Free Mass (FFM) • 24%-28% of weight-loss may come from FFM in diet only persons • 11-13% of weight loss from FFM in exercising dieters
Weight Maintenance Energy In = Energy Out Weight Stays the same
Best way to lose weight??? Weight loss through dietary means alone often lowers RMR due to loss of muscle (FFM). Weight loss from exercise can help to preserve and enhance FFM
Rate of Weight loss • Small changes, moderate losses, reasonable goals: • .5 to 2 pounds per week or 1% body weight/week • How much will you have to cut kcals to reach this goal? • 500 to 1000 kcals/day • Lean individuals who desire fat loss for appearance/performance will lose fat more gradually than the individual who has excess fat • Rapid weight loss in lean individuals can result in 3 times more lean tissue loss (FFM) than fat loss
Influences on Intakeand Eating Behavior • Diet composition—amount of macronutrients (protein, fat, carbohydrate), fiber, energy density • Gastrointestinal sensations—stomach and intestinal distension • Hormonal and neurological factors—neuropeptide Y, serotonin, ghrelin, leptin • Cognitive, social, and environmental factors—eating with others, clean-plate club • Hidden factors—plate, bowl, or cup size
Assessment of Body Weight or Fatness • Height–weight tables • Body mass index (BMI) • Body composition • Skinfold measurements • Dual-energy X-ray absorptiometry (DXA) • Hydrodensitometry (underwater weighing) • Bioelectrical impedance analysis (BIA) • Body-fat distribution • Waist circumference • Waist-to-hip ratio • Body image
Social Stigmatization and Psychological Health • In the United States, fat is generally considered to be a negative attribute that is under a person’s control. • The ideal body is thin and lean or muscular. • Stigmatization of overweight and obese people is widespread and may be worsening over time. • Consequences include reduced self-esteem and negative body image. • Health at Any Size is an acceptance movement. How Might Each JoggerBe Viewed by Society?
Size Acceptance • Health at Any Size (HAAS) is a size-acceptance movement that attempts to help large people be healthy. • A study of more than 25,000 men found that cardiorespiratory fitness was a better predictor of heart disease than body weight was. • A study of women also found that lack of physical activity was a better predictor of heart attack than weight was.
Effective Weight Management • Set sensible goals. • Develop a healthy weight management lifestyle. • Eat healthy by being aware of nutrition value and calories of food. • Be physically active. • Know how to modify your eating behavior. • Take advantage of self-help opportunities.
Dieting Patterns in the United States • Weight cycling (yo-yo dieting) • Popular diets • Low-carb, high-protein diets • Low-fat diets • Novelty diets • Very-low-calorie diets • Healthy weight control programs not “diets”
Maintaining Weight Loss Findings from National Weight Control Registry of people who have maintained a weight loss of at least 30 lb (13.5 kg): • Consume slightly less than 1,400 calories. • Engage in high levels of physical activity. • Monitor weight.
Times When It’s Hardto Maintain Weight • Entering college • Getting married • During and after pregnancy • Holidays
Inappropriate Methods for Weight Loss • Spot Reduction • Saunas, sweat suits and body wraps • Vibrating belts • Electrical stimulators • Fad and starvation Diets
Packaged foods, food combinations, supplements, exclusion of certain foods or food groups/macronutrietns • Any diet will lead to weight loss if energy intake is reduced • Potential increased loss of lean body mass • High risk for nutritional deficiencies • Long term efficacy, safety, maintenance is unknown
Changing the Obesogenic Environment • Community organizing and action • Schools and workplaces • Media and advertising • Food packaging and labeling • Financial and economic incentives • Transportation and urban and rural development