Do Diet Programs Prevent Disease Risk?

Diet and exercise interventions to reduce obesity may not help stave off disease since people tend to gain the weight back, according to a new report. Dr. Lennert Veerman and colleagues note the focus of such programs may need to change if they're really going to have a lasting effect.

To test the potential impact of different diets, the researchers ran two computer simulations on an overweight and obese population in 2003: one included a low-fat diet, the other a diet rich in whole grains and vegetables plus 180 minutes of exercise per week.

Outcome measures were disability adjusted life years (DALYs) averted, incremental cost-effectiveness ratios (ICERs) and proportions of disease burden avoided.

According to the models, people lost an average of 8 to 12 pounds on the diets and kept the weight off for an average of 6 months. But the pounds slowly crept back on, and after less than 6 years, the dieters were back where they started -- negating any improvement in health from the weight loss.

In addition, the researchers estimate that only about 3% of Australia's population would participate in weight-loss programs.

Dr. Veerman of the University of Queensland in Brisbane stated that, "Interventions that try to change the behavior of individuals but do nothing about the environment in which these people live, are likely to have modest and temporary effects at best." "They are not the solution for the obesity epidemic -- more, and different, interventions have to be taken."

Along with continued counseling to help people keep weight off long-term, Dr. Veerman suggests a 'junk food tax' and better nutrition labeling. These did seem to have an overall positive effect on health in a parallel study, published in November in the same journal.

Dr. Hollie Raynor, associate professor of nutrition at the University of Tennessee in Knoxville, who was not involved in the study, noted that, "We understand that weight loss programs that we have now are really helpful for individuals, but the challenge seems to be how do we help individuals maintain this weight loss over time?"

Dr. Veerman concluded, "The fact that not everybody (who's) overweight wants to, or can, participate reduces its overall effect on the overweight-related burden of disease in the population."

International Journal of Obesity. Posted online January 11, 2011. Abstract