Metabolism and Aging

If you’ve noticed that your metabolism has seemed to slow as the years have flashed by, you are not imaganing things, and you aren’t alone. The speedier metabolisms seem to go to males, rather than females; those who exercise regularly, rather than those who don’t; and to younger people, rather than older people.

Research from the USDA Nutrition Center on Aging at Tufts University, has shown that after age 24, adults typically gain from 0.4 to 1.7 pounds per year. It is estimated that after we turn 25, we start losing the lean muscle mass that has kept our metabolisms running at full speed in prior years. By our 4th and 5th decade, it’s not unusual to have to let the belt out a couple of notches, and a slowing metabolism plays a role in that.

There’s been a lingering debate about why metabolism slows as people age. A broad study funded by the Agricultural Research Service found that as people age, there is a gradual loss of those high-energy-consuming muscle cells that help our body burn calories; thus, older people burn fewer calories, and the weight tends to creep up.

But the blame probably rests more on lowered activity levels, than on age. In our middle years, increased job demands often require sitting at a desk for long hours every weekday, with little time, or energy, remaining at the end of the day for exercise. Also, a hectic schedule all too often leads directly to the drive-through window at the local fast food chain on the way home, rather than to a balanced, home cooked meal at the end of the day.

The good news is there are ways to regain some of that youthful metabolic rate we were blessed with when we were younger; ways to keep those metabolic fires burning; and some hope of getting off that slow train to obesity.

The first, and maybe the hardest point, is that older people regain some of their youthful metabolic rate through regular muscle-building exercises. Just about anything you do to keep moving, and increase lean muscle mass, will pay benefits in your metabolic rate. For example, to start building muscle mass, use your ten minute work breaks to walk around the building, or start lifting light weights, in the morning before work, or in the evening as you watch television.

Sleep also plays an extremely important role; a study published in PloS Medicine found that the amount of sleep you get affects your metabolism. If you shortchange your sleep, the resulting increase in the hormone ghrelin, which triggers hunger and decreases energy expenditure, will tempt you to over eat.

Researchers have found that as we get older, the best chance we have to burn fat, and speed up our metabolism, is to eat five or six very small meals a day. These should be spaced three to three and a half hours apart throughout the day. Eating in this manner causes our metabolism to work harder than if we ate the usual three larger meals we are used to. Our daily food consumption might look something like this: Possibly a whole grain cereal for breakfast, and then a yogurt or a handful of nuts at midmorning; lunch might be some sort of salad including protein, perhaps chicken or fish; then, as an afternoon snack, string cheese, or other low fat cheese; dinner might be a stir fry including whole grain pasta and again some variety of protein.

To live a healthier life as you age, nutrition and exercise are the key, there is no quick fix or temporary solution.