Women who lose 10% or more of their body weight through diet and exercise must engage in 275 minutes per week of physical activity to maintain that weight loss beyond the initial 6 months, according to a report.
The level of physical activity needed to sustain weight loss over the long term “is about twice the public health recommendation” of 30 minutes of moderate-intensity activity on most days of the week, said Dr. John M. Jakicic of the University of Pittsburgh's Physical Activity and Weight Management Research Center and his associates.
They studied the effect of exercise on weight loss in 191 overweight women who participated in a 2-year intervention. They were aged 21-45 years, were sedentary, and had a body mass index of 27-40 kg/m
The women were prescribed a 1,500-calorie per day diet and were assigned to one of four levels of exercise. They attended weekly group meetings focused on strategies for modifying eating and exercise behaviors for the first 6 months of the intervention and monthly meetings thereafter. They also received brief periodic phone calls from the intervention team for support and encouragement.
A total of 170 subjects (89%) completed the full 2 years of the intervention. Weight loss and regain was similar across all categories of exercise intensity and duration.
As a group, they lost a mean of 8 kg by 6-month follow-up, then gradually regained about half of that amount so that the mean weight loss totaled 4.2 kg at 2 years.
Exercise followed the same pattern as weight fluctuation, increasing for the first 6 months of intervention and gradually decreasing over time. “The inability to sustain weight loss appears to mirror the inability to sustain physical activity,” said the authors (Arch. Intern. Med. 2008;168:1550-9).
Subjects who achieved and maintained a weight loss of 10% or more of their initial body weight—only 25% of the total—engaged in at least 1,800 kcal/wk of physical activity, which corresponds to 275 minutes a week above their baseline level of activity. The findings clarify the amount of physical activity necessary to achieve and sustain weight loss and demonstrate the difficulty women have in sustaining this level of activity, the authors added.
Women need 275 minutes of exercise a week to maintain their weight loss. ©Andres Rodriguez/