The news is heavy. The figures are huge. One in every three Americans today is obese, and a study published in the Journal of Health Economics in January estimates that $190.2 billion a year is spent on obesity-related healthcare costs alone. Worse yet, experts predict the obesity rate will rise. Nearly half of the American population—42 percent, to be exact—will be obese by 2030.
That is the dire forecast of a study published in May in the American Journal of Preventive Medicine. But, researchers say, should the obesity rate remain steady and not continue on its upward trajectory, it could save the country almost $550 billion in healthcare costs in the next two decades. Prevent another 32 million Americans from becoming obese and far fewer of them will get sick.
Obesity—defined as a body mass index (BMI) of 30 or more—increases the risk of such chronic conditions as heart disease, stroke, cancer, and diabetes. According to the Centers for Disease Control and Prevention, chronic diseases are the leading causes of death and disability in the United States, but they are also among the most preventable.
Today, the U.S. Preventive Services Task Force, an influential panel of medical experts, is emphasizing the need for doctors to screen all adults for obesity, whether through calculating height and weight to determine BMI or measuring their waist circumference—women with a waist size greater than 35 inches and men with a waist size greater than 40 inches are at a higher risk for obesity-related diseases. And those who are diagnosed as obese are now advised to undergo intensive behavioral interventions like weight-loss counseling—at least 12 to 26 sessions in the first several months. Upon review of many weight-loss studies, the Task Force found evidence of positive weight-loss results when patients engaged in at least a dozen sessions in the first year. So what steps can a person take to lose the weight? Research is yielding fresh insight.
A recent survey of obese adults who were trying to drop pounds found that 40 percent were able to lose at least 5 percent of their body weight, while 20 percent were able to lose at least 10 percent. "We were surprised by [the number of] obese Americans who said they lost enough weight to have a significant health benefit," says Jacinda Nicklas, lead author of the study published in April in the American Journal of Preventive Medicine and a clinical research fellow at Beth Israel Deaconess Medical Center and Harvard Medical School. Guidelines from the National Institutes of Health advise obese adults to lose 10 percent of their body weight for improved health, but studies show that even a loss of 5 percent is beneficial. (A May report in Cancer Research found that postmenopausal women who were overweight or obese and lost at least 5 percent of their body weight experienced a reduction in inflammation, which is associated with the development of cancer.)
Participants who lost at least 5 percent of their body weight reported that they ate less fat, exercised more, and used prescription weight-loss medications, though the latter was used by a small number of participants. Those who lost 10 percent or more of their body weight were more likely to have joined a weight-loss program. Nicklas suspects that the association between such programs and successful weight loss may be because "when people join a weight-loss program, they often make a commitment of time and money, and that helps motivate them to stick with it. They also benefit from the accountability of being weighed and the support of a program, which can help when weight loss becomes challenging." And while each of these strategies—eating less fat, exercising more, joining weight-loss programs, and using prescription weight-loss medicines—had an independent effect on weight loss, most of the participants were using at least two.
Liquid diets and nonprescription weight-loss pills were found to be less helpful. As were popular diet programs like the Atkins Diet, the Zone Diet, or the Grapefruit Diet—a low-carb, high-protein food plan featuring grapefruits—among other diets the researchers gave participants as examples. Popular diets, says Nicklas, may have worked for some people, but when examined as a whole, they were not associated with significant weight loss. And participants who reported eating diet foods or products were less likely to achieve a 10 percent weight loss. Nicklas attributes this to a possible "health halo" effect. Because these foods are labeled "diet" or "low-fat," people tend to believe they have fewer calories or are healthy, and will therefore overeat.