You hear a lot of talk about “metabolism” these days. But what exactly is it?
“The sum total of all the workings of the body,” says Diane Kress, a registered dietician and author of The Metabolism Miracle. From cell maintenance and reproduction to food digestion and fat burn, your metabolism is everything your body does to stay alive, Kress explains.
All those life-sustaining processes require energy. So, in simplistic terms, if your metabolism is cranking at a high rate, your body will consume more energy—or calories.
You typically hear about “speeding” or “boosting” metabolism through physical activity. Kress says there’s a good reason for that. “Exercise lights a fire in your cells that increases your metabolic rate for about 12 hours,” she says. Nothing else you do has such a profound effect on your metabolism. (Your genes play a huge role in your metabolic rate, which explains why some people have no trouble staying slim.)
Along with exercise, the foods you eat can play a role in your metabolism. But there’s a lot of misinformation out there, Kress says. “You hear about spicy foods raising metabolic rate,” she says. “That’s true. But the increase only lasts for about three minutes, so there’s no benefit.”
Here are 11 foods or food-related habits that meaningfully improve your metabolism:
Even very slight dehydration slows your metabolic rate, Kress says. And the older you get, the more your ability to detect dehydration tends to lag. Aim to drink at least 64 ounces of water a day—more if you’re working out. “Make sure to drink eight ounces for every 30 minutes of your workout,” she advises. Raise that to eight ounces per 15 minutes of exercise in hot weather.
Multiple studies have tied cinnamon to improved insulin sensitivity and metabolism, as well as lower rates of weight gain and diseases like diabetes. Cinnamon helps your body absorb glucose efficiently, which prevents fat storage, says Manuel Villacorta, a registered dietician and author of Peruvian Power Foods.
This healthy whole grain is high in fiber and protein. Both produce a “high thermic effect”—meaning they increase metabolism and require effort and time for your body to digest, Villacorta says.
These morning favorites are one of nature’s healthiest sources of protein, which—again—requires more energy to digest than fat or carbohydrates, Kress says.
Caffeinated coffee drinkers enjoy a 16% hike in caloric burn compared to decaf or non-coffee drinkers, Kress says. That metabolic uptick can last as long as five hours. Sipping a cup in the morning and another in the afternoon is a good idea—provided the caffeine doesn’t mess with your sleep, Kress says.
Rich in B vitamins and zinc, both of which increase metabolism and calorie-burning muscle development, Villacorta says. “B vitamins act as coenzymes—the helper compounds that assist in the activation of our metabolism,” he says.
This Peruvian herb contains essential amino acids and calcium, all of which support a speedy metabolism, Villacorta says. There’s evidence maca also promotes blood glucose absorption, which cuts down on your body’s fat storage.
The green tea antioxidant epigallocatechin gallate (EGCG) enhances energy expenditure and fat oxidation, according to a study from the University of Chicago. That enhanced metabolic activity can last for two or three hours, Kress says. She recommends drinking a few cups spread throughout the day.
While the research on the benefits of breakfast seems to seesaw back and forth, Kress is firmly in the “breakfast is best” camp. Why? The longer your body goes without fuel in the form of food, the more its metabolic rate slows, she says. She recommends things like whole grain toast with peanut butter, fruit, or—of course—eggs.
REACH FOR THE RIGHT GRAINS
Processed grains are a “pre-digested food,” Kress says. They slide right through your digestive system, and so require little energy to break down. The opposite is true of whole grains, she says. When it comes to bread, rice, pasta, or other grain-based staples, whole grains are always your healthiest option.
CUT OUT LOW-CALORIE DIETS
Healthy dieting is about choosing the right calories, not eating fewer of them, Kress says. Why? When you cut calories, your body goes into “starvation mode.” You may drop a few pounds initially. But because your diet is restricting its access to energy, your body will begin storing up those calories you do consume like a squirrel preparing for winter. Also, your metabolic rate may reset at a lower rate—meaning a return to your former diet will cause you to regain weight in a hurry, Kress says. “The average male should consume, at minimum, 1800 calories a day,” she says.