Almost two-thirds of Americans are either overweight or obese. Although it’s true that sedentary lifestyles and lack of exercise put us at risk for weight gain, it’s also true that many Americans are eating and drinking more than ever before.
“More than one of every four Americans is obese,” says Samuel Klein, M.D., the Danforth Professor of Medicine and Nutritional Science and director of the Center for Human Nutrition at Washington University School of Medicine in St. Louis. “During the past 10 years, the prevalence of obesity in adults in the United States has continued to increase, in spite of more and more research about the dangers of being overweight and more people trying to lose weight. The obesity problem is a major public health crisis.”
Obesity puts people at risk for heart disease, diabetes, stroke, high blood pressure and cancer. It also decreases quality of life.
And a major factor contributing to increasing body sizes appears to be increasing portion sizes. The Department of Agriculture’s “Continuing Survey of Food Intake by Individuals” reveals that the portion sizes of most foods and beverages have increased significantly over the last two decades.
“Both at restaurants and at home, Americans eat and drink more,” Klein says. “Increased food intake and decreased physical activity because of sedentary lifestyles are responsible for the obesity epidemic.”
Consider these statistics. Compared with eating habits in 1977, on a per-serving basis, today’s average American consumes:
• 93 more calories per serving of salty snacks (e.g. potato chips, pretzels and popcorn)
• 49 more calories per serving of soft drinks
• 97 more calories per serving of hamburgers
• 133 more calories per serving of Mexican food (burritos, tacos, enchiladas)
“And keep in mind that just 10 extra calories per day will cause a person to gain a pound of fat per year,” Klein says. “Part of the problem is that many of us tend to eat what is put in front of us, and more is being put in front of us than ever before.”
Solid food isn’t the only problem either. In 1973, 7-Eleven introduced its popular Gulp drinks in two sizes: 12- and 20-ounces. Today, the drinks come in four sizes. The standard Gulp is 16 ounces. The Double Gulp comes in at 64 ounces — that’s half a gallon!
Many soda machines that once sold 12-ounce cans now sell 20-ounce bottles. In 1976, most beer bottles held 7 ounces. Now, bottles come in 7-, 12-, 22- and 40-ounce sizes.
Losing weight safely
Klein and his colleagues at the Washington University Weight Management Program use the most current information to help people lose weight safely and reduce long-term risks of obesity-related diseases by providing group classes, medical monitoring, nutrition education seminars and exercise education seminars. Individual counseling sessions and long-term maintenance also are included.
Klein also studies the best methods of trying to lose weight. He was part of the first multicenter trial to look at the low-carbohydrate, high-fat/protein Atkin’s diet. In that study, researchers found that at three and six months, the Atkin’s diet produced significantly greater weight loss than a conventional low-fat, high-carbohydrate diet.
Atkin’s dieters lost twice as much weight during the first six months. However, over the next six months of the study, dieters on both plans tended to regain weight, and there was no statistical weight difference between the groups at one year because most were no longer sticking to their diets.
The same research team has begun a longer study comparing the Atkin’s diet to more traditional, low-fat diets. The five-year National Institutes of Health-funded study of low- and high-carbohydrate diets is recruiting participants to help the researchers more fully assess the benefits and risks of the diets on bone mass, kidney function, blood vessel health and exercise tolerance. The researchers also are studying whether behavior intervention and modification might help people stick to these diets.
Because of the high amounts of fat that people consume on the Atkin’s diet, many have worried that over the long term, it might have serious side effects. The initial study found no differences in side effects over 12 months and even found benefits in blood lipid profiles. The new study will look more closely at the benefits and side effects, following and examining participants who have been on the study diets for two years.
But while scientists investigate the best ways to lose weight, Klein says the easiest way to prevent obesity and its complications is not to gain weight in the first place. He says it’s important for people to be aware of how much they eat and drink, and to realize that although supersizing may seem like a bargain for food, it can lead to significant costs in terms of health.