Maintenance of weight loss is a core problem in the treatment of obesity. Physical activity may improve maintenance and metabolic risk factors associated with obesity.
(1) A walking training program of moderate intensity, started after weight reduction by a very-low-energy diet, improves maintenance of weight loss and obesity-related metabolic disorders; and (2) the effect of the training program is related to the prescribed amount of physical activity, ie, a higher amount (energy expenditure) leads to more favorable results.
The participants were premenopausal women with a mean body mass index of 34.0 kg/m2. Eighty-two participants were randomized to this study; 74 participated in the follow-up assessment. A 12-week weight reduction by mostly a very-low-energy diet was followed by a 40-week maintenance program randomized in 3 groups: a control group with no increase in habitual exercise and with counseling on diet and relapse prevention; a walk-1 group, with a walking program targeted to expend 4.2 MJ/wk and diet counseling; and a walk-2 group, with a walking program of 8.4 MJ/wk and diet counseling. Random permuted blocks within strata were used, with weight loss (in 3 classes) as the stratifying factor. After the intervention, the subjects were followed up for 2 years.
Main Outcome Measures
Primary outcomes were body weight, fat mass, and waist circumference at the 2-year follow-up. Secondary outcomes were the levels of serum lipoproteins and lipids, plasma glucose, insulin, and blood pressure.
The mean weight loss after weight reduction was 13.1 kg. The main outcome variables remained stable during the maintenance program, but increased during the follow-up period. Compared with the end of weight reduction, weight regain at the 2-year follow-up was 3.5 kg less (95% confidence interval, 0.2-6.8) and waist circumference regain 3.8 cm less (95% confidence interval, 0.3-7.3) in the walk-1 group vs controls. The secondary outcomes showed a partial relapse during the maintenance program, and a further regain during the follow-up period.
Inclusion of a walking program of moderate training regimen into a weight maintenance program improved maintenance of losses in weight and waist circumference.