Study finds physicians need to understand the American struggle with long-term weight loss

Kraschnewski JL. Int J Obes. 2010;doi:10.1038/ijo.2010.94.

Issue: February 2011

Only about one in every six Americans who have ever been overweight or obese loses weight and maintains that loss, according to Penn State College of Medicine researchers.

While that number is larger than most weight-loss clinical trials report, the majority of Americans are still unable to lose weight and keep it off. Identifying those who lose weight and successfully maintain that loss may aid health professionals in developing approaches to help others maintain weight loss, researchers stated in the study which was published in the International Journal of Obesity.

Two-thirds of the U. S. adult population is overweight, with a BMI of at least 25, or obese with a BMI of at least 30. Obesity rates have doubled between 1980 and 2004, according to a Penn State University press release.

Need to change

Weight loss and weight maintenance programs need significant changes in their effectiveness and availability to affect these numbers, the researchers noted.

“It is important for health professionals to understand the true prevalence of long-term weight loss, as it may help to change the underlying beliefs and influence clinical practice,” Jennifer Kraschnewski, MD, MPH, assistant professor of medicine and public health sciences, said in the release. “Studies have shown that physicians may not believe offering weight-loss advice and counseling is a worthwhile activity in clinical practice. An awareness of our findings may encourage health professionals to pursue weight-loss counseling for overweight patients.”

Long-term loss

Penn State College of Medicine researchers analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2006. Participants of this survey self-reported weight status and history.

Researchers calculated BMI for each individual and determined if they achieved 5%, 10%, 15% or 20% weight loss maintenance for more than 1 year. The sample included 14,306 people: 52.3% men and 47.7% women. One-third stated a current goal of losing weight, with 82.6 percent classified as overweight or obese.

Thirty-six percent of the sample had maintained a weight loss of at least 5% of their initial body weight. This is a higher rate than reported clinical trials, the researchers noted. This difference may be that while those who participate in clinical trials are a selected population, the numbers in the current study include unintentional weight loss, or the current study captures temporary weight gain that is typically lost at specific instances, such as the so-called “freshman 15.”

In the sample, women, adults aged 75 to 84 years, non-Hispanic whites and those with less than a high school education showed stronger longer-term weight management.

“Identifying a significant percentage of the population that is succeeding in some weight loss may be an important target population for weight maintenance programs,” Kraschnewski said. “Although the amounts lost are modest, if a substantial number of individuals achieved such losses, it would have a significant public health effect. Particularly, those individuals who have lost at least 5% and kept it off — one in three Americans who have ever been overweight — may represent a unique opportunity to reach a target population who has had some success but could benefit from greater weight loss efforts.”

Other key findings of this study: Women had a higher prevalence of a long-term weight loss of at least 10% than men, married or partnered individuals had a lower prevalence; and 69% of those who reported losing at least 10 lb the previous year said it was intentional with intentional weight loss more likely to be in younger individuals, females, non-Hispanic whites, those with greater than high school education, and those with a history of diabetes or better overall health.

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