The basic principles of losing weight are simple. In order for the body to burn fat, it’s necessary to consume less calories than you burn.
This is a simple thermodynamic principle- when the body is provided with less energy via dietary intake than it needs to maintain the body, it will harvest the deficit from the energy stored in fat, resulting in overall weight loss.
The practice of this principle, however, is more difficult than it sounds. The average adult requires between 2000 and 2500 calories every day for maintenance, which drops to between 1500 and 2000 calories for weight loss.
Performing regular physical exercise in addition to adhering to a caloric restricted diet will increase the total amount of energy your body requires, resulting in increased weight loss.
This process, however, can lead to some unwanted effects, such as increased fatigue, low energy levels, and hunger pangs.
It’s important to ensure that, while on a weight loss diet, you provide your body with all of the nutrients and vitamins it needs to stay healthy.
There are a number of foods, however, that are actually able to increase the metabolic rate of the body, increasing the amount of energy you burn during the day while at the same time providing essential nutritive elements.
Called thermogenic foods, these ingredients can make the process of weight loss easier and faster, bringing you closer to your health and fitness goals.
In this article, we’ll find out how thermogenic foods speed up the fat loss process and provide a comprehensive list of the ten most effective thermogenic ingredients you can use to increase your base metabolic rate.
What Are Thermogenic Foods?
Thermogenic foods are types of food that require the body to exert additional energy to break down and digest, or foods that increase the metabolic rate of the body.
The rate at which these foods affect the body is determined by the thermic effect of the foods.
A good example of a thermogenic food is celery, which is commonly labeled as a “0 calorie food”. When the body digests celery, it requires more energy to break down than it provides once digested, resulting in a net energy loss.
The thermic effect of food isn’t determined solely by the amount of energy it takes to break down, however. Other factors such as portion size, meal frequency, and the nutritional content of the food can affect its thermic value.
Smaller meals have been proven to deliver an advantage over larger meals- a clinical investigation performed in 1997 found that the thermic effect increases when meals are divided into smaller portions.
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Organic Thermogenic Foods
Some foods contain naturally-occurring organic compounds that are able to stimulate a thermogenic response in the body outside of the thermic effect of the food itself.
Antioxidant polyphenols, amino acids, capsaicinoids, and methylxanthines have all been clinically proven to increase thermogenesis in a wide range of scientific clinical trials[2], so by consuming these foods it’s possible to get an additional calorie-burning boost that aids in your weight loss endeavor.
Foods that are rich in protein are highly thermogenic, as they require the body to exert a large amount of energy to break them down.
Protein rich diets have been demonstrated in multiple clinical trials to increase the rate at which the body can burn fat[3], which is attributed in part to the thermic effect of these foods and partly due to the effect protein has on satiety and appetite.
Adding thermogenic foods into your diet is an effective strategy when paired with a healthy diet and physical activity plan that will speed up your weight loss efforts significantly.
10 Powerful Thermogenic Foods
It’s important to maintain an awareness of the basic requirements of your body with regards to diet when attempting to lose weight.
Ensuring you’re providing your body with the right amount of protein, carbohydrates, fats, vitamins, and minerals will go a long way to keeping your digestive system functioning efficiently, which has a significant impact on your base metabolic rate.
Incorporating foods that provide these nutrients in addition to delivering a thermogenic effect will enhance your overall metabolic function, ease hunger pangs, reduce appetite, and help your body recover from exercise faster.
Let’s take a look at the top 10 most powerful thermogenic foods that are available at your local grocery store:
1. Chicken
Chicken is extremely rich in protein content, which has been demonstrated to deliver a significant thermogenic effect.
One cup, or roughly 140 grams of chicken breast, contains 38 grams of protein, which amounts to roughly half the recommended daily intake.
The thermic effect of protein is roughly 20% to 30%, meaning that almost one third of the energy that is supplied by chicken is used to digest it.
When compared to the base thermic effect of carbohydrates, which sits at around 5% to 7%, it’s clear that protein offers a significant advantage when seeking fat loss.
There are many diets that involve removing carbohydrates almost completely from the diet and instead providing the body with a high amount of protein, such as the Paleo diet and the Keto diet.
There is a large body of scientific evidence that proves the high thermic effect of chicken breast.
The thermogenic effect of chicken, however, has been demonstrated to deliver a more effective thermic effect when prepared in a specific fashion.
Removing any excess fat from chicken before you cook it, and avoiding using fat-rich oils has been shown to deliver a more powerful thermic effect overall[1].
If you’re following the vegan or vegetarian lifestyle, it’s still possible to gain a large amount of protein without eating meat. Tofu, tempeh, beans, nuts, and oat flour are all extremely rich in vegetable protein, which also has a potent thermic effect.
There are also many pea protein powder supplements available on the market that make it easy to increase your protein intake while following a restricted diet.
2. Peppers
Hot peppers, chili, and black pepper all contain a naturally-occurring substance called capsaicin, which is responsible for their spicy flavor.
Interestingly, capsaicin emerged from the natural evolution of plants as a deterrent to prevent animals from consuming them, but has ironically led to the widespread cultivation of capsaicin foodstuffs as it is particularly piquant to the human palate.
In addition to providing an interesting flavor sensation, capsaicin-rich peppers have the ability to deliver a powerful thermogenic effect.
This unique compound has been found to deliver a negative energy balance of over 20% in several clinical trials[2], and is able to significantly increase fat oxidation.
Unlike protein, capsaicin causes thermogenesis not by requiring more energy to break down, but by agitating key receptors in the adrenal system, promoting an overall increase in metabolic function[3].
Aside from the increase in thermogenesis spicy food can deliver, foods that are rich in capsaicin also offer a wide range of other health benefits.
Clinical trials investigating the health effects of capsaicin consumption have found that it is able to boost cardiovascular health, protect from heart disease[4], promote better digestive system function, prevent cancer, and act as a powerful anti-inflammatory agent[5].
Foods that are rich in capsaicin are cayenne peppers, chili peppers, tabasco peppers, paprika, and green peppers.
It’s also easy to add capsaicin to your meals with any hot sauce, but be sure to pay attention to the nutritional content of any sauce you may add, as many are rich in sugar.
While capsaicin may deliver a wide range of health benefits, it’s important to use a degree of caution when ingesting it.
Although capsaicin can be ingested in extremely large doses with no ill effects- a popular youtube trend involves consuming incredibly large amounts of super-powerful capsaicin-dense peppers- capsaicin has the ability to irritate the mucous membranes of the digestive system if consumed excessively and cause uncomfortable bowel movements.
Eating too much capsaicin also carries the risk of disturbing the microbiome of your digestive system, which is composed of billions of microorganisms that assist with digestion and immune system function- so be sure to consume capsaicin in moderation.
3. Coffee
Coffee contains a high amount of caffeine, which is a proven thermogenic compound. There are several clinical trials that provide conclusive scientific evidence of the thermic effect of coffee.
An investigation performed by the Research Department of Human Nutrition in Denmark in 1990 found that ingesting caffeine causes the body to produce higher levels of lactate and triglycerides, which results in increased thermogenic function[6].
The thermogenic properties of caffeine function differently to the capsaicin compounds found in spicy foods.
Instead of antagonizing adrenoceptors, caffeine simultaneously delivers an increase in the total amount of energy burned while providing an additional boost in energy available by increasing fatty acid uptake[7].
This means that coffee is able to both increase base metabolic rate as well as improve the efficiency with which the body breaks down fat deposits for energy.
One standard cup of coffee contains roughly 100 mg of caffeine.
A clinical trial performed by the University of London in 1989 found that repeated consumption of 100 mg doses every two hours throughout the day is able to increase overall energy expenditure by 8% to 11%, resulting in an additional 150 calories burned over the day[8].
This trial was performed over a 12 hour period, however, which resulted in a 600 mg total daily dose.
Caffeine has been demonstrated to be safe to consume in amounts of up to 800 mg daily with no negative effects[9], but as dosage can vary depending on the strength of the coffee bean and preparation method, it’s best to stick fo 2-4 cups daily at maximum.
4. Green Tea
Like coffee, green tea is another thermogenic compound that is able to boost the metabolic rate of the body with caffeine.
Unlike coffee, however, green tea also contains a number of other compounds that cause a thermogenic effect that aren’t linked to caffeine.
The thermogenic effect of green tea is provided partly by caffeine, and partly by naturally-occurring chemical compounds called polyphenols.
These polyphenols, also referred to as tannins, add the astringent flavor to green tea, and are present in many foods and drinks such as rosemary, olive oil, or red wine.
The polyphenols in green tea are unique– called catechin polyphenols, they are able to stimulate thermogenesis in a different manner than caffeine.
When green tea polyphenols are absorbed by the body, they inhibit the release of an enzyme called catechol-O-methyl-transferase, which the body uses to break down a key neurotransmitter called noradrenaline.
Noradrenaline is used by the body to regulate the levels of a messenger molecule called cyclic AMP, or cAMP, which plays an integral role in the weight loss process[10].
By stopping the body from decreasing the levels of noradrenaline and increasing cAMP levels, green tea polyphenols boost the production of an enzyme called hormone-sensitive lipase, which has been demonstrated to significantly increase the rate at which the body is able to break down fat through a process called lipolysis[11].
Aside from the scientific evidence available that demonstrates the biological mechanisms that cause green tea to induce thermogenesis, several clinical trials have observed a direct link between green tea consumption and fat loss.
A clinical investigation performed at the University of Geneva in 1999 found that green tea consumption increases the 24-hour energy expenditure of the body by 4% and is able to deliver greatly enhanced fat oxidation[12].
Many more clinical trials point to green tea as a healthier and more effective alternative to coffee as a thermogenic compound[13].
Evidence suggests that drinking three cups of green tea delivers the greatest thermogenic effects, as well as offering protection from oxidative stress and heart disease.
5. Leafy Greens
Leafy greens are commonly incorporated into healthy weight loss diets due to their rich nutritional content and powerful antioxidant properties.
Like chicken, the composition of leafy greens requires a great deal of energy for the body to digest, and have been demonstrated to offer a wide range of health benefits that can promote faster weight loss.
One of the major health benefits offered by leafy green vegetables such as lettuce, spinach, and salad greens is their rich carotenoid content. Carotenoids are responsible for the rich coloring of leafy greens and offer a number of health benefits.
Compounds such as beta-carotene, lycopene, and lutein are common carotenoids that are found in many leafy greens in high levels, with almost one full gram of carotenoid per 100 grams of leafy greens[14].
Carotenoids have been proven to induce thermogenesis and improve the rate at which the body is able to metabolise fat deposits[15].
Other clinical trials have also demonstrated the ability of leafy greens to balance blood sugar levels and reduce the absorption of fat from food, minimizing total caloric intake[16].
An interesting trial performed in 2015 found that leafy greens contain compounds called thylakoids inside the cellular membranes of the plant tissue.
These compounds have been proven to minimize appetite response and help dieters feel more satisfied after eating leafy greens, further reducing caloric intake and lowering the threshold at which fat burning occurs[17].
Incorporating leafy greens into your diet is a simple and easy way to increase the thermogenic levels of your body.
6. Water
Drinking water, especially cold water, is able to increase the overall energy expenditure rate of the human body.
While the difference made in terms of caloric consumption due to drinking cold water is minimal, it is a proven effect that can increase your total energy consumption throughout the day.
Multiple clinical trials have provided concrete evidence that consuming more water increases thermogenesis[18].
A Swiss clinical trial performed in 2015 found that drinking 500ml of water can cause an energy expenditure increase of 3% in just 90 minutes after consumption[19].
Another German investigation performed in 2003 found that drinking 400 ml of extra water beyond maintenance consumption levels increases metabolic rate by a massive 30%, resulting in a net burn of 95 extra calories[20].
Lowering the temperature of the water you drink has also been demonstrated to deliver a more powerful thermic effect.
A meta-study of more than 40 clinical investigations into the metabolic effect of water consumption performed in 2012 found that lowering the temperature of water by just three degrees celsius results in a 5% increase in overall energy expenditure[21], meaning ice water is able to provide a calorie-burning boost to dieters.
Ensuring you get enough water is essential to maintaining overall health and delivers a wide range of health benefits, so if you’re trying to lose weight, drinking more cold water is a great way to improve your metabolic rate and boost energy levels.
7. Eggs
Eggs are almost as high in protein as chicken. One egg, at around 50 grams, contains about 6 grams of protein, which works out to almost one tenth of the total recommended daily intake.
Eggs are also comparatively low in calories, with one egg containing just under 80 calories in total.
There is a great deal of scientific evidence to support the use of egg as a thermic agent- a trial performed in 1984 found that the MJ protein found in eggs delivers a thermic effect that is three times as powerful as the thermic effect delivered by carbohydrates[22].
The thermic effect delivered by egg protein has also been demonstrated to lower appetite by increasing the sensation of satiety after a meal[23].
High protein diets help dieters feel fuller for longer, reducing the likelihood that they will consume more food and increase their total caloric consumption for the day.
Incorporating the eggs into the diet to boost fat burning thermogenesis is best done with either hard boiled or poached eggs, as frying eggs generally requires fatty oils, which negate the thermic effect of the food.
Scrambled eggs are another healthy alternative to fried eggs that serves as a low-GI, protein rich breakfast, providing slow-burning energy all day long.
8. Turmeric
Turmeric is a member of the ginger family, and has been used in traditional Indian Ayurvedic medicinal cooking for thousands of years.
This unique root spice offers a wide range of health benefits including anti-inflammatory and prodigestive properties, but has a potent thermogenic ability that is able to speed up the fat loss process.
The thermogenic properties of turmeric are delivered by a compound it contains called curcumin.
Bright yellow in color, curcumin is responsible for the unique appearance and flavor of turmeric, and is a popular herbal supplement due to the health benefits it offers.
Similarly to capsaicin, curcumin interacts with the adrenoceptors of the body to induce thermogenesis and contribute to fat burning.
One teaspoon of turmeric powder contains about 100 mg of curcumin, which has been demonstrated in clinical trials to cause a significant increase in the weight loss capacity of the body[24].
The high curcumin content of turmeric has also been shown to modulate cyclic AMP levels in a manner similar to the polyphenolic catechin antioxidants found in green tea.
A recent 2017 clinical investigation has found that curcumin supplementation at 500 mg daily results in a significant increase in cAMP production, delivering a boost to energy expenditure, the breakdown of fat, and thermogenesis[25].
The powerful thermogenic effects of turmeric can be multiplied by consuming it in combination with black pepper, which contains a compound called piperine.
Piperine, aside from functioning as a powerful thermogenic agent in itself[26], plays a complementary role in the body and can increase the effectiveness of curcumin in causing a thermogenic response[27].
9. Coconut Oil
Coconut oil has exploded in popularity over the last few years due to the broad spectrum of nutrients and health-enhancing applications it offers.
Made by processing white, fleshy meat of the coconut, coconut oil contains high levels of medium chain fatty acids that have a proven thermogenic effect.
Roughly 60% of the fatty acid content of coconut oil is composed of MCT oil, but newer manufacturing methods have made MCT oil rich coconut oil extractions widely available recently.
A 1989 clinical trial investigating the effect of medium chain triglyceride fatty acids on the metabolism found that consuming 150% of the recommended daily intake of MCT- about 60 grams- results in a 15% energy expenditure increase[28].
Increased medium chain triglyceride consumption has been demonstrated in multiple clinical trials to boost the metabolic and thermogenic rates of the body.
A clinical trial performed in 2008 by the New York Obesity Research Center found that supplementing the diet with between 18 and 24 grams of MCT leads to increased fat loss.
Adding coconut oil to your diet can be achieved by adding it to coffee or hot drinks, in smoothies, homemade energy bars, in Southeast Asian cooking and stir fry dishes, in baking, or as a healthy substitute for cooking oil.
Keep in mind, however, that as coconut oil is high in caloric content, is should be treated like other cooking oils and used sparingly.
10. Apples
Apples, aside from providing the body with essential nutrients and minerals, are extremely rich in dietary fiber. There are two types of dietary fiber- soluble and insoluble.
Apple fiber consists of roughly 80% soluble fiber, which can be digested by the body and dissolves in water. This digestion process, however, requires a large amount of energy to perform, which gives apples a high thermic value.
One apple contains, on average, about 4.4 grams of dietary fiber.
A clinical trial performed in 1987 found that supplementing the diet with just 6 grams of dietary fiber every day is able to significantly increase energy expenditure[29], leading to a 23% increase in thermogenic rate.
Apples also contain a type of organic fiber called pectin. Pectin has been shown to reduce appetite, with doses as small as just five grams able to significantly reduce appetite response for several hours[30].
Eating just two apples daily will increase your dietary fiber and pectin intake, boosting energy consumption and burning fat.
Thermogenic Foods Summary
Increasing the thermogenic rate of your body is a highly effective way to boost your metabolism and increase the speed at which your body is able to burn fat.
If you make an effort to follow all of the tips in this guide, it’s possible to increase your overall daily caloric expenditure by 25% to 30%, which can make a huge difference when trying to shake off unwanted body weight.
While eating thermogenic foods is not going to cause you to lose weight while following a caloric deficit diet at the same time, they definitely provide a helpful boost.
Combine thermogenic foods with a caloric deficit diet and regular physical exercise for the best effect, and always make sure you’re giving your body enough sleep, water, and micronutrients.
By making healthy lifestyle choices and remaining focused, weight loss can be easy, simple, and delicious.
[1] https://www.ncbi.nlm.nih.gov/pubmed/24477248
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3699483/
[3] http://www.nature.com/ijo/journal/v34/n4/full/ijo2009299a.html
[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4477151/
[5] https://www.ncbi.nlm.nih.gov/pubmed/25675368
[6] https://www.ncbi.nlm.nih.gov/pubmed/2333832
[7] https://www.ncbi.nlm.nih.gov/pubmed/22710994
[8] https://www.ncbi.nlm.nih.gov/pubmed/2912010
[9] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3742445/
[10] https://www.ncbi.nlm.nih.gov/pubmed/10702779
[11] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2885771/
[12] https://www.ncbi.nlm.nih.gov/pubmed/10584049
[13] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4025876/
[14] https://www.ncbi.nlm.nih.gov/pubmed/8988807
[15] http://www.sciencedirect.com/science/article/pii/S0003986115000843
[16] https://www.ncbi.nlm.nih.gov/pubmed/24064726
[17] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4539357/
[18] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4728633/
[19] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4735055/
[20] https://www.ncbi.nlm.nih.gov/pubmed/14671205
[21] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3542490/
[22] https://www.ncbi.nlm.nih.gov/pubmed/6476790
[23] https://www.ncbi.nlm.nih.gov/pubmed/9683329
[24] https://www.ncbi.nlm.nih.gov/pubmed/26362189
[25] https://www.ncbi.nlm.nih.gov/pubmed/27355903
[26] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2714833/
[27] https://www.ncbi.nlm.nih.gov/pubmed/9619120
[28] https://www.ncbi.nlm.nih.gov/pubmed/2739575
[29] https://www.ncbi.nlm.nih.gov/pubmed/3032832
[30] https://www.ncbi.nlm.nih.gov/pubmed/9322190
