The more inactive we become with age, the less lean muscle we have. The less lean muscle we have, the more inactive we become. Over the years, the two feed on each other, and our metabolism plummets. Unless you have thyroid disease, which can play havoc with how your body burns energy, you can get your metabolism cranked up again by making some lifestyle changes. But first, here's what's going on inside.
Men burn calories faster for two reasons.
One, they are usually heavier and are burning more calories all the time. Two, they have a greater proportion of fat-burning muscle. As a result, the average basal metabolic rate in women is 5 to 10 percent lower than in men. Men are also more likely to put on fat around the belly, which happens to be the easiest location to lose fat. This further slows down our metabolism.