As we get older, it can be harder and harder to stoke the fire of one’s metabolism. It’s just something that happens naturally over the years, but for many, it can be a frustrating fact to say the least, especially if you have goals you’d like to reach. As many people know, fad diets aren’t the best way to go about losing weight—specifically, Cleveland Clinic says that often, these diets aren’t well-researched, or the research is faulty.
Instead, it’s best to focus on tried-and-true certainty, and that’s good nutrition. In addition to fueling your body and feeling your best through plentiful nutrients, there’s another approach you can consider as well: eating thermic foods.
“Studies have found that protein exerts an ‘increased thermic,’ or calorie-burning, effect when compared with carbs and fats,” says Paul Kriegler, RD, Director of Nutritional Product Development at Life Time. “This means that our bodies use more energy to digest and burn protein than carbs or fat.”
This way of eating centers around minimally processed protein and fiber-rich foods, which can also result in appetite control. Read on to find out how the food you eat can light the fire of your metabolism.
What is a thermic food?
Nona Djavid, a nutrition and weight loss expert and founder of SoulScale, a 28-day meal- based weight loss program, explains the thermic effect of food like this:
“Some of the calories in the food you eat are used to digest, absorb, metabolize, and store the remaining food, and some are burned off as heat. This process is known under various names, one of which is the thermic effect of food (TEF).”
Kriegler says that, for example, protein has a thermic effect of 30 percent, adding, “This means that if you eat a lean-protein food that has 100 calories, nearly 30 calories are used to digest and process the food.”
Carbohydrates have a thermic effect of 10 to 15 percent, while dietary fat has the lowest thermic effect of only 3 percent, but Kriegler says that it’s important to keep in mind that healthy fats and carbs are still essential to proper nutrition.
What impacts a food’s thermic effect?
There are several factors that come into play during the thermic process.
Djavid says, “The TEF represents about 10% of the caloric intake of healthy adults who eat a standard mixed-macronutrient diet, but the actual number will depend on several factors, including your age and the meal timing, and macronutrient composition—carbs, fat, and protein—of your meal.”
Simply put? The thermic effect can depend on several influences, but generally, these high-protein foods can be beneficial to one’s metabolism, something that’s been proven through scientific research.
In addition to other factors like meal size and physical activity, for the specific composition of one’s meal, Kriegler says that protein and fiber content have the biggest impact on thermic effect. “The higher the percentage of calories eaten from protein, the higher the thermic effect of the dietary pattern,” he says.
Fish and seafood
Wild salmon, sardines, anchovies, shrimp, lobster, halibut, mackerel, and other types of fish and seafood are all high in protein along with other nutrients that are critical to healthy metabolism, like creatine, selenium, and iodine, as Kriegler says. They also contain omega-3 fatty acids, which help reduce inflammation.
“Seafood has a very high protein content and may perhaps be the best fat burner,” Djavid says. “Like other proteins, for every 100 calories consumed from seafood, close to 30 calories are spent during digestion and absorption.”
Beef, bison, and wild game
Kriegler says that beef, bison meat, and other forms of wild game are forms of “muscle meats and organs,” foods that are high in protein and are also rich in nutrients, including iron, carnitine, creatine, and B-vitamins, things that all work together for a healthy metabolism.
Additionally, Djavid explains that legumes have a high fiber content, which reduces insulin spikes, something that can result in improved glycemic control.
“Blood sugar dysregulation is a big component of weight gain and obesity, among many other chronic health conditions,” she says.
Dark meat poultry
Although you’ve probably trained yourself to eat the white-meat chicken over the years, if you’re after thermic results, you’ll want to serve yourself dark meat instead. Kriegler says that dark meat is “high in protein and rich in carnitine and creatine, which can help upregulate the capacity to burn fat for energy.”
It’s time to start your day off right—with a plate full of eggs that promise a thermic effect.
“With more than 6 grams of protein per egg, they’re another great option,” Djavid says. “Just like lean meats, protein-rich foods tend to have a higher thermogenic effect than their carbohydrate or fat-based alternatives.”
Kriegler adds that eggs also contain vitamin D, vitamin E, iron, choline, and other nutrients critical for a good metabolism.
Cheese is no longer on the “do not eat” list—you can absolutely grab a slice of Swiss or cheddar as part of your thermic eating approach. It’s ideal since it’s high in protein, calcium, and potassium, which can all boost one’s metabolism, according to Kriegler.
Even though they taste as sweet as sugar, sweet potatoes can be great for producing a thermic effect—just be sure to skip the marshmallows or sprinkle them with moderation.
Djavid says that sweet potatoes have the ability to reduce insulin resistance, something that can increase blood sugar.
Plain yogurt is a home run when it comes to thermic foods. Perfect to eat on-the-go or as a satisfying breakfast, Kriegler notes that unsweetened, plain yogurt is high in protein and calcium.
If you’re looking for a good source of carbohydrates to add to your diet that’s also high in protein and fiber, look no further than lentils, another type of legume. Kriegler says that when eating lentils, the protein and fiber combine for a relatively high thermic effect and high satiety.
Yum! Cottage cheese is not off the table when approaching your diet with thermic foods.
“Studies have found that a high protein diet consisting of egg whites, turkey, cottage cheese, and tuna elicited a twofold increase in postprandial thermogenesis at 2.5 hours post-meal compared to a high carbohydrate diet,” Djavid says. In other words? When combined with other protein-rich foods, cottage cheese is a thermic powerhouse.
Coffee and green tea
When unsweetened, morning starters coffee and green tea can have thermic benefits for the body. In fact, these beverages stimulate body temperature and heat production and may help release fat from body fat stores to be burned for energy, as Kriegler explains.
Nuts of all kinds can act as thermic foods.
“We all know that nuts have a pretty hefty calorie and fat tag attached to them, but they may be worthwhile to consume,” Djavid says. “Aside from being loaded with healthy fats and protein, it turns out they also have a thermic effect.”
If your palate can handle it, spicy foods are proven thermic foods. Specifically, look for foods that contain capsaicin, like chili peppers, or ginger, things that can “stimulate blood flow and body heat production to help with burning extra energy, potentially from fat stores,” Kriegler says.
Djavid shares that aside from reducing inflammation and improving cardiovascular health markers, studies have also shown capsaicin ingestion elicits a positive effect on metabolic rate, respiratory quotient, and appetite. Bring on the hot sauce!
“Extensive research has shown that curcumin, the active constituent of turmeric, is an effective control for obesity due to its direct interaction with adipocytes, or fat cells, pancreatic cells, hepatic stellate cells, macrophages, and muscle cells,” Djavid says. Curry dishes and Indian meals tend to brim with turmeric.
MCT oil, which stands for “medium-chain triglyceride,” is considered to be more of a supplement rather than the olive oil you have in your pantry. Typically derived from coconut or palm oil, it contains easily digestible fat cells that people often add to the popular “bulletproof coffee,” a Keto favorite that also includes brewed coffee, milk, butter or ghee, and collagen powder.
Djavid explains that given the shorter length of the triglycerides in MCT oil, they’re rapidly metabolized and absorbed directly into the bloodstream and travel directly to the liver, where they are then converted into energy, or ketones.