Just last week, I chided a friend about skipping meals in an attempt to lose a few pounds. “It slows down your metabolism, so you’ll just gain weight,” I reasoned. “How does it do that?” she wanted to know. “Well … it … okay, I don’t know. But it does!” I responded, rather sheepishly.
Anyone who has picked up a health or fitness magazine has read about the need to keep our metabolisms “revved up” to burn calories efficiently and that certain bad habits—like waiting too long in-between meals or omitting them altogether—are detrimental to the cause. All too commonly, the actual explanations for why our metabolic rates increase and decrease are edged out by diet buzz words and cheesy motivational messages. Perhaps if we understood the basic workings of the metabolism and how our actions affect it positively or negatively, it would be easier to adopt the lifestyle changes necessary for keeping it at an optimal rate.
I consulted Manuel Villacorta, MS, RD, CSSD, a registered dietician with Nutrition for You, to find out the answers to the most common questions his clients have about the mighty metabolism.
What’s a metabolism?
Metabolism refers to your body’s ability to digest and utilize food energy (in calorie form) in order to maintain essential bodily functions like breathing and regulating heartbeats. “It’s the amount of calories that your body uses to make sure that it’s continually surviving,” Villacorta explains. One’s metabolic rate is determined by how quickly it can use up consumed calories, and that rate is affected by a variety of factors: age, weight, exercise, eating habits, and so forth. In order to condition our metabolisms to perform at peak levels, we must address each of these factors when coming up with a plan.
Are people really born with fast or slow metabolisms?
“Metabolic rates vary based on genetics,” he says. “It’s kind of like your fingerprint.” However, that doesn’t mean that metabolic rates are set in stone. Just like other genetic predispositions, they can be affected by making certain lifestyle choices, such as eating well and developing more muscle mass. The more muscle mass one has, the higher the metabolic rate. Villacorta likens muscles to bundles of cells that are “like engines creating energy.” He says that metabolic functions can increase by fifty calories for every pound of muscle gained.
Why do I put on weight more easily now than five years ago?
Even if our eating habits don’t change over our lifetimes, we still are more likely to put on weight as we age. That’s because our metabolisms naturally slow down as we get older. Therefore, if we want to maintain our weights, we have to adjust our calories accordingly as the years pass. “About every ten years, metabolic rate decreases about 10 to 15 percent,” Villacorta says. “So when [my clients] in their forties say, ‘My old tricks aren’t working anymore,’ I tell them it’s because their metabolic rates have completely changed.” He advises that people reevaluate their diets at these points to keep the pounds off.
Is an apple a good snack?
Fruit is always a great idea for a snack, but an apple or a banana alone might not be as beneficial as we think. Incorporating different food groups into a snack actually makes our bodies work that much harder at digesting everything, thereby increasing our metabolic rates. “You want to keep your body working all the time,” Villacorta explains. “If you have an apple, add some almonds and low-fat cheese.” He finds that many people eat too minimally in the hopes of losing weight. A plain salad with chicken seems like a healthy choice, but he actually says this is one of the worst meals one could eat. With a meal like that, “you’re not adding grains or fats, which help your metabolic rates,” he says. “It’s the combination of things that help; not just having one thing.”
