Be careful not to confuse thermogenesis with negative calorie foods. Negative calorie foods are said to burn more calories during digestion than they contain. The thermic effect of food is calculated as a percentage of calories consumed. So let’s say you get your thermic effect up to 20%. This means that a 500 calorie meal will give you an excess of 400 calories (since 20% will be burned off during the digestive process). Doubling that amount will double the amount of calories burned in the digestive process, but it will also double the amount of excess calories you consume. The goal here is to reduce excess calories.
- Lean Proteins – If you eat 100 calories from fat, your body will burn 3 calories during the digestive process. If you eat 100 calories from carbs, your body will burn off about 10 calories during digestion. If you eat 100 calories of protein, your body will burn off about 25 calories during the digestive process. Animal proteins have a greater thermogenic effect than plant based proteins. However, plant based proteins do a better job of helping you feel fuller for longer.
- Hot Peppers – Not only does the capsaicin in the hot peppers increase thermogenesis directly after they’re consumed, but they have also been shown to slightly increase your resting metabolic rate. The greatest concentration of capsaicin isn’t in the seeds, but the white pith surrounding the seeds.
- Spices – Black pepper (piperine), turmeric (curcumin), mustard seeds, ginger, garlic, and cinnamon have all been shown to temporarily increase your body’s heat production. Put these on your foods and mix them in your drinks to give your metabolism a temporary boost!
- Green Tea – Studies published in the American Journal Of Clinical Nutrition have shown that the catechins contained in green teas increase energy expenditure. In fact, one study had a 17% increase in fat oxidation in the group that consumed the green tea.
- Coconut Oil – The University of Geneva conducted a study that shows 15 to 30 grams of coconut oil a day (consistently) can increase your daily energy expenditure by 120 calories. This is because coconut oil is made of medium chain triglycerides. Medium chain triglycerides are quickly absorbed and readily burned as fuel. In 2010 ‘The International Journal of Food Sciences and Nutrition’ proved again that medium chain triglycerides encourage weight loss by increasing energy expenditure over long chain triglycerides.
You can maximize diet induces thermogenesis by doing a few things. Eat your calories in a few larger meals rather than spacing those same calories out over the course of several smaller meals. More importantly, eat the same amount of meals each day that each contain about the same amount of calories. Another thing, that we should be doing anyway, is exercise. Resistance and aerobic endurance exercise not only boost your metabolism by themselves, but they also increase the effect of diet induced thermogenesis.
Sources: Clegg ME. “Medium-chain triglycerides are advantageous in promoting weight loss although not beneficial to exercise performance.” Int J Food Sci Nutr. 2010 Nov. http://ajcn.nutrition.org/content/70/6/1040.full. Denzer, CM; JC Young (September 2003). “The effect of resistance exercise on the thermic effect of food.”. International Journal of Sport Nutrition and Exercise Metabolism 13. Farshchi HR, Taylor MA, Macdonald IA. Decreased thermic effect of food after an irregular compared with a regular meal pattern in healthy lean women. Int J Obes Relat Metab Disord. 2004 May;28(5):653-60. Tai MM, Castillo P, Pi-Sunyer FX. Meal size and frequency: effect on the thermic effect of food. Am J Clin Nutr. 1991 Nov;54(5):783-7. Physiol Behav. 2006 Aug 30;89(1):85-91. Epub 2006 Mar 30. Pharmacol Res. 2010 Mar;61(3):208-12. doi: 10.1016/j.phrs.2009.11.007. Epub 2009 Nov 30. http://www.ncbi.nlm.nih.gov/pubmed/8654328