What are Thermogenic Foods?

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What are Thermogenic Foods?

Last update: 17 June, 2020

These days, you’ll find lots of different weight loss methods being touted, but many of them lack any real scientific evidence to support them. So, are thermogenic foods just another one of these false hopes?

To understand what thermogenic foods are, we need to look at the basics of thermogenesis and other concepts. For example, how can you calculate the amount of energy that your body needs?

What is energy expenditure?

Energy expenditure is the amount of energy that the body needs to carry out day-to-day activities. To find out what it is, you need to consider three things: your basal metabolic rate, the thermogenesis of the food you eat, and the amount of physical activity you do.

Basal metabolic rate

Basal metabolism is the minimum amount of energy needed to maintain the body’s vital functions when resting. These include things such as breathing, blood circulation, or maintaining body temperature. For children, it includes the energy required to grow.

Although this represents the majority of the energy we need, there will be variation between individuals depending on their body composition, gender, and age. For example, two men of the same height and weight won’t have the same basal metabolism. Particularly if they have different body compositions.

Muscle tissue is metabolically more active than fat tissue. Therefore, a person with more muscle will need more energy than someone with a lower percentage of muscle mass.

To calculate this parameter, you can use either direct methods or indirect methods. Indirect methods are more common because they’re easier. One of the most popular is the Harris-Benedict equation, which estimates the basal metabolic rate using your weight, gender, and height.

Someone having their belly fat measured.


Diet-induced thermogenesis is the energy required to carry out the processes of digestion, absorption, and metabolism after meals. It can account for between 10 and 15 percent of your energy needs. The amount this varies by depends on the types of food you eat.

This means that the energy expenditure for digesting a meal rich in carbohydrates or proteins is greater than that for a meal rich in fats. Furthermore, this value decreases with age, probably due to the increase in insulin resistance.

Physical activity

Physical activity is the third component of energy expenditure and, in many cases, the most important. This value includes the energy consumed in both voluntary and involuntary activities, such as shivering.

This is the form of energy expenditure that you have the most control over since it largely depends on your lifestyle. For sedentary people, the thermal effect of physical activity can be as low as 100 kCal/day, whilst very active people can reach 3000 kCal/day.

So what are thermogenic foods?

Thermogenic foods are any substance capable of increasing body temperature. Some of the most well known thermogenic foods are coffee, green tea, coconut oil, cinnamon, and chili peppers.

Eating these foods is associated with increased energy expenditure. This is because eating them increases body temperature, and mammals have to keep this temperature constant.

Thermogenic foods are sometimes marketed under the name of “fat-burning foods”. This is because of their ability to increase body temperature and it also means that the body consumes more energy.

If nutrition were this simple, it would mean that any food capable of increasing body temperature could increase resting energy expenditure. However, this isn’t the case.

A pot of cinnamon, which is one of many thermogenic foods.

What does science say about thermogenic foods?

If you search for information on thermogenic foods on a scientific database, such as Pubmed, one of the main search engines for scientific studies, what you’ll find is that research focuses on specific ingredients. When a substance is shown to increase basal metabolism, this usually relates to data obtained in vitro or from microdoses. As a result, it’s difficult to extrapolate these results to the human body.

So, even though the thermogenic theory is clear, scientific evidence doesn’t support the use of thermogenic foods as a stand-alone weight-less strategy. However, you can include it alongside other lifestyle changes, such as increased physical exercise.

Therefore, thermogenic foods can be included in your diet, but make sure they don’t add more calories. It may not be a silver bullet, but it’s certainly another technique you can use.

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