For people who embark on weight-loss programs, keeping weight off is even harder than losing it. A new study found that about five hours of exercise per week makes it easier for overweight women who lose weight to keep it off.
Prescription for weight loss
The study, published in the Archives of Internal Medicine, included 201 overweight and obese women from 21 to 45 years old. The women were instructed to limit calories to 1,200 to 1,500 per day, and calories from fat to 20 to30% of total intake. Participants were divided into groups that engaged in four different levels of exercise intensity. Extra support was provided through regular support group meetings and telephone check-in calls with members of the intervention team. They were followed for two years.
The women lost an average of 17.8 pounds (8.1 kg) in the first six months, but only 9.2 pounds (4.2 kg) remained off after two years. Energy expenditure through exercise similarly increased early in the study, but dropped back to near baseline by the end.
It’s the follow-through that counts
The original exercise group assignment had no bearing on how much the women were exercising at the end of the study. When the women were grouped according to actual exercise, those who maintained the highest energy expenditure kept the most weight off. For these women, adding approximately 55 minutes of exercise per day, five days per week, to their regular daily activities was associated with sustained weight loss of 10% or more of their baseline body weight.
The researchers noted two other differences between the women who sustained 10% or greater weight loss and those who didn’t: they completed more telephone calls with the intervention team between months 6 and 24, and they reported sticking to weight-loss eating behaviors, such as self-monitoring of food intake and weight, not eating food from others, eating in only one place, and avoiding nighttime and emotional eating. Having extra support may have helped them stick to their exercise and eating behavior plans more closely.
Tips to keep it off
“This study showed how difficult it is to sustain weight loss of 10% or more of initial body weight, as fewer than 25% of the women in this study met this criterion at 24 months,” concluded lead study author Dr. John Jakicic of the University of Pittsburgh. “Relatively high levels of physical activity appear to contribute to sustained weight loss, and our findings help to clarify the amount of exercise needed for achieving and sustaining this degree of weight loss.”
The results support the recommendations set forth by the US Department of Agriculture in their 2005 Dietary Guidelines for Americans, which states that 60 to 90 minutes of daily moderate-intensity physical activity, in addition to calorie restriction, is needed for sustaining weight loss. Below are some other steps that help keep the weight off:
• Keep a daily food diary that records the amounts and types of foods eaten and the situations in which you eat. Awareness of the circumstances that lead to eating unhealthy foods and overeating provides the opportunity to make changes that encourage better weight-loss eating habits.
• Control portions, especially of fatty and starchy foods. Filling up on low-calorie foods like vegetables and fruits may help.
• Eat slowly—this allows you to recognize fullness before you’ve overeaten.
• Keep an exercise journal that shows your success and challenges in meeting exercise goals.
• Get regular support from a group, and consider enlisting the help of a trainer or weight-management specialist to keep you on track.
(Arch Intern Med 2008;168:1550–9)
Maureen Williams, ND