The World Health Organization describes obesity as “an escalating epidemic” and one of the greatest neglected public health problems of our time (see Figure 9-2). Because obesity is a disease with multiple health risks, such as type 2 diabetes, heart disease, and some forms of cancer, the increasing rates of obesity are projected to result in increased rates of disability and preventable deaths.3 One of the national health objectives for Healthy People 2010 is to reduce the prevalence of obesity among adults to less than 15 percent.
Although many factors (including genetics) influence body weight, excess energy intake and physical inactivity are the leading causes of overweight and obesity, and they represent the best opportunities for prevention and treatment.4 Consider how the following trends in our society have increased opportunities for poor nutrition (particularly excess calories) and decreased opportunities for physical activity:
¦ Food portion sizes and obesity rates have grown at the same rate. In the 1960s, an average fast-food meal of a hamburger, fries, and a 12-ounce cola provided
ASK YOURSELF ANSWERS: 1. False. Being thin is good for health only to a point; being too thin is as risky as being too fat. 2. True. 3. False. A high weight according to the scales and the so-called ideal weight tables may reflect heavy bones and muscles rather than excess fatness. 4. False. If you are too fat, it could be because you exercise too little. 5. False. Basal metabolism contributes about 60 percent or more of the average person’s daily energy output. 6. True. 7. True. 8. True. 9. False. Although you may lose weight quickly on a fad diet, much of the weight you lose may be muscle or water and the weight may soon be regained when the diet ends. 10. False. People with anorexia nervosa are constantly hungry but control their eating.
O No data < 10%
20%-24% 25%-29% > 30%
The Epidemic of Obesity among U. S. Adults
Note the increasingly upward trend of obesity among the 50 states. In 1991, no states had obesity rates of greater than 20 percent, and only 4 states had obesity rates greater than 15 percent. By 2000, only 1 state (Colorado) had an obesity rate of less than 15 percent, and 22 states had obesity rates greater than 20 percent. In 2007, just 1 state had an obesity rate of 15-19 percent; 19 states had rates of 20-24 percent; and 30 states had rates more than 25 percent; three of these states (Alabama, Mississippi, and Tennessee) had a prevalence of obesity equal to or greater than 30 percent.
SOURCE: U. S. Obesity Trends 1985-2007, Centers for Disease Control and Prevention; available at www. cdc. gov
590 calories; today, supersized fast-food meals deliver 1,500 calories or more.5 Even an extra 150 calories a day—the calorie cost of supersizing a soft drink—can convert to about 16 extra pounds of body fat every year.
¦ Vending machines selling soft drinks, high-fat snacks, and highly sugared snacks are common in schools and workplaces. Milk, juices, water, and healthful snacks are far less accessible.
¦ Adults spend more time in sedentary activities, such as watching television, working on the computer, or commuting to and from work and school.
¦ Children watch 12 to 14 hours of television a week and spend 7 hours playing video
¦ Schools offer fewer physical education classes for children.
¦ More families live in communities that are designed for car use but are unsuitable (lack of green space for recreation) and often unsafe (lack of sidewalks, inadequate street lighting) for activities such as walking, biking, and running.