An hour a day of moderate exercise is needed to maintain weight and
overweight women need to diet as well as exercise, a Harvard team reports in the Journal of the American Medical Association.
The authors say clear guidelines on the amount of physical activity for the prevention of weight gain are essential.
They draw two conclusions: “Firstly once overweight, it may be too late because physical activity – at least, at levels carried out by study participants – was not associated with less weight gain.
“Secondly, sustaining high levels of physical activity (60 minutes a day) is needed to successfully maintain normal BMI and prevent weight gain.” This level of activity is higher than the minimum that the UK government recommends.
But Professor Paul Gately, who runs Carnegie Weight Management Programme at Leeds Metropolitan University, said the government recommendation is the amount of exercise needed to reduce risk of ill health.
He said more exercise was needed to avoid weight gain, and an hour a day was in line with findings of previous research.