(HealthDayNews) -- The next time you're tempted to reach for that candy bar, remember this bit of depressing news from the American Journal of Physiology:
The calories that you burn off don't matter, but 85 percent of all the extra calories you eat -- the ones that you don't burn up -- are converted directly to fat.
If you under-eat, your metabolic rate will slow down to conserve energy -- that's why it can be hard to lose weight. But it only works one way. If you over-eat, your body won't speed up to help burn it off.
