Do some foods speed up your metabolism?

 

As we have learned, the thermic effect of food (TEF) is the energy consumed when your body is digesting and processing food. It can, to a small extent, be influenced by the composition of our diet and the types of food we eat. The primary determinants of daily TEF are the total caloric content of our meals and their macronutrient composition, whereas meal frequency has little to no effect. It has been claimed that, in obese individuals, TEF is reduced, meaning they miss out on the effect of burning calories to offset intake, but to date research has failed to validate this. 

The thermic effect of protein is the highest, with 20 to 35% of the energy provided by protein being required for its digestion and absorption. The thermic effect of carbohydrates averages between 15 to 20% of the calories in those foods and will depend on whether they are simple sugars or complex starches, as well as the amount of fibre present. Most easily digested are fats, which have a thermic effect of only 5%. This means that your net caloric gain from fats averages 95% of their total calories, compared with a net caloric gain of about 70% of the calories found in lean protein. 

Some foods, such as celery, are often claimed to have negative calories (requiring more energy to digest than is recovered from the food), but there is no evidence to support this hypothesis. One recent study from Oxford Brookes University investigated the thermic effects of chilli and coconut oil (which contain a type of fat known as medium-chain triglycerides, MCT). The researchers concluded that adding chilli and MCT to meals increases TEF by over 50% which over time may accumulate to help induce weight loss and prevent weight gain. 

How to speed up your metabolism

While some people turn to certain food and drinks in the hope of speeding up their metabolism, others are resigned to the belief that there is nothing they can do and that they have just been dealt an unlucky genetic hand. While there are certain factors you can't change, such as your age or your height, you can change your body composition by building more muscle, and this in turn will speed up your basal metabolic rate. Muscle tissue burns more calories than fat tissue, so increasing your muscle mass will help you lose weight. Two sessions of muscle-strengthening exercise per week should be sufficient to achieve results. The exercise should work all major muscle groups (legs, hips, back, abdomen, chest, shoulder and arms) - for instance lifting weights and high-intensity interval training (HIIT) workouts. 

Aerobic activity will also speed up metabolism, not only through the calories burned while you are exercising but also through the effect of the afterburn, when the body continues to burn calories for a number of hours after the exercise has stopped. Some people who are said to have a fast metabolism are probably just more fidgety than others. As NEAT can account for such a major chunk of calories burned, it clearly pays to be constantly busy.