(HealthDay)—For an underserved primary care population, a high-intensity lifestyle-based treatment program for obesity results in significant weight loss at 24 months, according to a study published in the Sept. 3 issue of the New England Journal of Medicine.

Peter T. Katzmarzyk, Ph.D., from Pennington Biomedical Research Center in Baton Rouge, Louisiana, and colleagues conducted a cluster-randomized trial to examine the effectiveness of a high-intensity lifestyle-based program for treatment delivered in primary care clinics. Eighteen clinics were randomly assigned to either provide patients with an intensive-lifestyle intervention, focusing on reduced and increased physical activity, or usual care (nine to each). The program included weekly sessions for the first six months followed by monthly sessions for 18 months. Overall, 452 patients were assigned to the intensive-lifestyle group and 351 to the usual-care group.

Of the participants, 67.2 percent were Black and 65.5 percent had a household income of less than $40,000. The researchers found that the percent weight loss was significantly greater in the intensive-lifestyle than the usual-care group at 24 months (change in , −4.99 versus −0.48 percent), with a mean difference between the groups of −4.51 percentage points. No significant differences were seen between the groups in serious adverse events.

"The results of this trial show the effectiveness of a high-intensity, lifestyle-based obesity treatment ," the authors write.

Several authors disclosed financial ties to the pharmaceutical industry.