Are you dreading getting fatter as you get older? Well it's not inevitable, say researchers from Northwestern University in the US. In fact the more active you are in your 20s and 30s, the lower your likelihood of gaining weight in your 40s and 50s.
Writing in the Journal of the American Medical Association, the researchers claim there are long-term benefits of taking regular exercise, and that the effects are greater for women than for men.
They studied 1,800 women and nearly 1,700 men over a period of 20 years, and discovered that women who had the highest level of activity gained an average of 13lb less than those who hadn't exercised as much (for men the difference was just 6lb).
"It's difficult to avoid gaining weight as you age," says Arlene Hankinson, one of the study's authors. "Our metabolic rate goes down. We develop conditions or have lifestyles that make it harder to maintain a high level of activity."
"Our study reinforces that everyone needs to make regular activity part of their lifestyles throughout their lives," she adds.
So how much exercise should you do now to avoid piling on the pounds when you're older? It's difficult to say, the researchers admit, but a minimum of 30 minutes a day is something to aim for.
They also don't suggest which type of exercise is best for avoiding middle-age spread. However, finding an activity that you enjoy may be the key to keeping it up in the long term.
Have you managed to find a type of exercise that you can stick to?