Between the late 30s and late 40s, it's not uncommon for both men and women to gain 10 pounds. The gain may come on relatively suddenly, or more gradually, at a general rate of one pound a year, even though you haven't made any major changes to your diet or exercise routine.
With age, both men and women gradually lose muscle mass. The loss of muscle mass at midlife is even more pronounced in men because of the loss of testosterone, a male hormone that regulates muscle mass and strength. In both men and women, however, the loss of muscle mass and strength usually leads to becoming less active.
The key to keeping excess pounds at bay at any age is a healthy diet and plenty of exercise, including strength training.
Dieting by slashing your calorie intake or manipulating your diet's ratio of fat, protein, and/or carbohydrates to shed pounds is perhaps the worst thing you can do to counter midlife weight gain.
Altering your intake of fat, protein, or carbohydrates also can further upset the balance your body needs at this time, inviting more hormonal hurricanes.
On the other hand, consuming more than 30 to 35 percent of your total daily calories as fat also can lead to weight gain since fat is a concentrated source of calories.
The solution is to make sure your diet contains small amounts of unsaturated, heart-healthy fat, which is found in olive and canola oil, fish, avocados, and nuts.
Your diet also should contain a mix of fruits, vegetables, whole grains, lean protein, and low-fat foods rich in calcium.
If you haven't started a strength-training routine yet, now is definitely the time to start a two- or three-day-a week program.
Weight training helps boost metabolism by reversing the natural loss of muscle mass that's otherwise part of the aging process. More muscle mass on board means your body burns calories at a faster rate, even when you're at rest.
To boost metabolism—the rate you burn calories—and control hormonally related cravings, it's also important to eat small, balanced meals or snacks about every three hours.
Keeping your diet and exercise in balance is really the key to maintaining a healthy weight.