Studies of exercise or physical activity, alone or as part of another intervention, aimed at preventing weight gain in older adults (aged at least 65 years) or post-menopausal women were eligible for inclusion. To be included, studies had to measure body weight or related outcomes with reference to preventing weight gain. Studies had to assess outcomes at least twice.
The included studies considered: self-reported exercise history; low, moderate or high intensity exercise; or combined exercise with a hypocaloric diet. Five studies were conducted in overweight adults; four were conducted in general population or not-weight specific population. Study types included randomised controlled trials (RCT), prospective study, secondary data analysis, and longitudinal survey. Forms of exercise in RCTs included moderate-intensity exercise, strength training, and walking. Forms of exercise in observational studies included sports, recreational exercise, housework, and manual labour. Six studies were in post-menopausal women and three were in older adults. Most studies were conducted in the USA. Data for included studies were collected from 1991 to 2007 (where reported). The reported outcomes included weight, waist circumferences, body mass index (BMI), and lean body mass.
Two reviewers independently performed study selection.