How does metabolism figure in?
You probably know people who seemingly eat whatever they want and never gain weight, and others who eat very little yet can't keep the pounds off. Are individual differences in metabolism to blame? To some degree, yes. But let's start with what is most likely not the problem. Metabolic disorders that prevent you from losing weight are rare. For example, the thyroid gland, which manages metabolism, often gets blamed for an inability to lose weight. Your thyroid can begin to work less efficiently as you age, so if you suspect a problem, get it checked. (Thyroidism runs incredibly high in my family--I get mine checked annually.)
Now let's look at what does affect metabolism. Genetics play a part, as does body composition. Lean muscle mass burns more calories than fat, so an athlete will possess a higher metabolism than a couch potato. (Men, being more muscular, tend to have higher metabolisms than women.)
Age affects metabolism, too. As the years go by, your organs, muscles, and bones become less efficient. Since the majority of your energy demands come from basic bodily functions, this slowdown lowers your need for fuel. After about age 25, your metabolism decreases by two percent for every decade that you live. We also all tend to lose muscle mass as we grow older, a process called sarcopenia. Because muscle mass burns more calories than fat, you need fewer calories to maintain your weight as your ratio shifts in favor of fat. Women approaching menopause must contend with yet another factor: Because fat, as well as ovaries, produce estrogen, a premenopausal woman's body starts to produce more fat cells to compensate for declining estrogen production from her ovaries.
All of that said, weight gain isn't inevitable, says Clark, especially if you're armed with awareness. Most often, if you don't understand why you can't drop the pounds, you're overestimating the calories you need--and underestimating the amount you eat. As you get older, be especially diligent about watching your intake and staying physically active, including weight-bearing exercise. If you work out consistently, you'll burn calories while also adding lean muscle and bone mass, which can have lasting effects not only on your weight but also on your health.
How can I keep track?If you want to stop overeating, don't trust your gut to tell you when you've reached your quota. "By the time we're adults we've eaten thousands of meals and are used to filling our plates with a certain amount of food, regardless of how many calories it contains." Studies reveal that when we're served a large portion, we eat more. They also show we're not good at guessing the number of calories in a given food. When you consider that downing an extra 50 calories a day can translate into five pounds a year, the significance of these misjudgements becomes apparent.
There's a simple solution, though. The surest way to know how many calories you eat is to count them. Online calorie counters can do a good deal of the work for you, and many are free. (One such site is
fitday.com.) Until you get more familiar with serving sizes, take the time to measure and weight what you eat as well. Don't forget the calories you drink--milk, juice, alcohol, and even certain water drinks add to the tally.
Granted, recording every single thing you eat probably seems like a drag. But the process gets easier as you go along. If you're a creature of habit who eats the same foods every day, that can work in your favor. Many online calorie counters let you review previous days and choose foods from a list of what you've already eaten. So if you liked Monday's 12-ingredient salad enough to have one again on Thursday, you just go back and check off the ingredients.
If you can't stand the thought of calculating every bit you take, simply write down what and when you eat--noting portion size instead of calories--in a notebook. Recording everything in this way has been shown to help weight loss.
Whew! What a lot. Maybe you should read this article twice. Or thrice. It certainly helps me to reread. Next Tuesday, I'll feature the third and final installment of this article: Energy-dense versus Nutrient-dense food. Does it really matter what kind of calories you eat?
Shaaaaazzaaaaaam! We have a winner!
