You lose about half a pound of muscle every year after the age of 35. Because muscle is more metabolically active than fat, it requires eight times more calories to maintain, even at rest. Therefore, as you lose more muscle you burn fewer calories. If all other factors remain constant, it translates into about 4 lbs of muscle lost and 15 lbs of fat gained every decade! Might just be a factor in midlife midriff expansion, don’t you think?

What you can do: If you include some strength training in your exercise program, you can reduce muscle loss. Each extra pound of muscle may burn an extra 50 calories per day, so it's worth doing some muscle-building exercises. In general, eat less fatty foods and exercise regularly to minimize fat gain.

Although hormone changes may be a factor in menopausal weight gain, a study published in Postgraduate Medicine concludes that "the factor most consistently related to weight gain in this age-group is decreased physical activity." Whether women get too tired or stressed to exercise, whether they lose interest and motivation, or whether they feel "too old" for it, the fact remains that most women decrease their physical activity at a time when they should be doing the opposite.

What you can do: Keep exercising, or start if you haven’t already. It’s also a good time to review what you do for exercise; it might be time to make some changes. Talk to a health professional or fitness expert and work out a plan that best meets your needs. This is especially important if you haven’t exercised in a long time. Remember that aerobic exercise can help boost your metabolism and burn fat, while weight-bearing exercise such as walking, jogging and dancing will also strengthen your bones and counteract bone loss, which helps defeat osteoporosis. You may want to try including strength training to help increase muscle mass and raise your metabolism. Exercise will improve your overall body shape, as well as boost your body-confidence. Apart from a little weight, you have nothing to lose when it comes to exercising!