If you're the type of person who feels ravenously hungry after even a half-hearted session in the gym - ravenously hungry for anything sweet, that is - you may never lose much weight by just exercising, say experts.
It doesn't take much to figure out why exercising might make you hungry, but why does it trigger some people's sweet tooth? Researchers from Queensland University of Technology in Australia asked themselves the same question
after studying a group of people on a 12-week exercise programme.
Just under half the group failed to lose as much weight as they should have. And the reason, claim the researchers, was that when they exercised, they had higher-than-normal cravings for high-fat, sweet foods such as cake, doughnuts and chocolate.
As a result, the researchers suggest that exercising to lose weight simply doesn't work in the same way for everyone.
Writing in the International Journal of Obesity, behavioural scientist Professor Neil King called those who lost weight as a result of exercising 'responders', as they tended to prefer eating low-fat foods after working out. Those who had increased cravings for doughnuts, on the other hand, were called 'non-responders'.
His findings, suggests Professor King, go one more step towards understanding why some people lose weight by exercising, while others don't. But if you're a typical 'non-responder', he says, that shouldn't stop you going to the gym.
"People should not be put off exercise," he says. "It still has other benefits such as better cardiovascular fitness and lower blood pressure."
What's your favourite post-work-out snack?