Exercising harder keeps weight off longer

NEW YORK (Reuters) -- People who consistently engage in high levels of exercise over the long haul are the most successful at losing weight and keeping it off, a new study shows.

Among a group of overweight men and women participating in an 18-month weight loss program, those who were still getting 75 minutes of exercise daily a year after the program ended had lost 26 pounds, compared with 1.8 pounds for people who were exercising less.

But only 13 of the 154 people who completed the study were able to sustain this level of activity, Dr. Deborah F. Tate of the University of North Carolina in Chapel Hill and her colleagues found. "Strategies are needed to help participants maintain high levels of activity over the long-term," she and her colleagues conclude in a report in the American Journal of Clinical Nutrition.

The researchers initially assigned 202 people to either a high physical activity group who aimed to burn 2,500 calories per week (equivalent to a 75-minute walk daily) or standard behavioral treatment, including 30 minutes of exercise daily, equivalent to 1,000 calories per week.

Twelve and 18 months later, people in the high activity group had lost significantly more weight than those in the lower activity group.

Although the participants in the high activity group were able to sustain the 2,500 calorie per week exercise goal during the 18-month study, their activity level declined once treatment ended, which resulted in no between-group differences in activity or weight loss at 2.5 years.

However, a small subgroup of people who stuck to the 2,500 calorie per week exercise regimen after the 18-month treatment period ended maintained a significantly larger weight loss than those who didn't exercise as much.

People who maintained high levels of exercise were also eating fewer calories and less fat.

The researchers believe that their e-mails, mailings and phone calls to study participants for the initial 18 months of the study were successful in helping them to reach exercise goals; continuing to stay in touch may have helped them sustain this level of activity.

"It is also possible that sustaining the long-term behavior changes that are needed for behaviors such as physical activity will require changes in the larger social and environmental context in which these behaviors occur," they conclude.