“Diet and exercise are a marriage that should never divorce,” said Giancoli, noting that the benefits of exercise aren’t restricted to the sheer number of calories you burn during thirty minutes on a treadmill. (Need one of those, by the way? We have some favorites.) Instead, research shows that muscle tissue burns more calories than fat tissue, proving that “muscle mass is a key factor in weight loss.”
Being healthy is really about being at a weight that is right for you. The best way to find out if you are at a healthy weight or if you need to lose or gain weight is to talk to a doctor or dietitian, who can compare your weight with healthy norms to help you set realistic goals. If it turns out that you can benefit from weight loss, then you can follow a few of the simple suggestions listed below to get started.
The problem is that when you rely on exercise alone, it often backfires, for a couple of reasons. This is partly because of exercise’s effects on the hunger and appetite hormones, which make you feel noticeably hungrier after exercise. “If you walk briskly for an hour and burn 400 kcal,” says Klein, “and then have a beer and a slice of pizza afterwards because the exercise made you feel hungry…you will eat more calories than you have burned.” It may not always be beer and pizza, but people do tend to naturally compensate for the calories they expend.
Just 10 extra pounds add 40 pounds of pressure on your knees and other lower body joints. That can wear them out quicker. Extra fat can also cause inflammation -- when chemicals in your body damage your own tissues over time, including your joints. Losing even a little weight can ease these effects. If you keep it off, you’re much less likely to get arthritis later in life.