Thermic effect of Food and Your Weight Loss Journey
A common myth within the weight loss community is that certain foods like cucumber or grapefruit can help you trim more fat, without any further dietary restrictions or regular exercise. These foods are considered “negative calories” since the body uses a significantly greater amount of energy to process nutrients than the food actually contains. This “negative calorie” trend started as more people became aware of the Thermic Effect of Food (TEF). While foods themselves can’t help you decrease body mass, understanding TEF can help make your weight loss journey more successful.
What is TEF?
Also known as Specific Dynamic Action (SDA) or Dietary Induced Thermogenesis (DIT), the Thermic Effect of Food is the amount of energy your body needs in order to actually eat foods and process their nutrients. This energy expenditure works in addition to your normal metabolic rate, so it can help you trim some fat off your body. However, the number of calories burned due to TEF varies and is generally not enough to make visible differences to your body. According to previous research, TEF accounts for around 10% of our daily energy expenditure (Tappy, 1996).
What affects TEF?
First and foremost, the number of calories, as well as the type of food and nutrients consumed, will play a large role in determining TEF. Based on the type of food you are eating, TEF can burn between 5% and 35% of the calories consumed (Glickman, Mitchell, Lambert & Keeton, 1948). Fats are easy to process require less energy have consequently lower TEF levels, while proteins are hard-to-process and need more energy (Barr & Wright, 2010). Proteins are also much more filling, so they will keep you satisfied longer which leads to reduced calorie intake.
Staying active can increase your TEF levels. With exercise, you can burn around 7-8 extra calories per hour with TEF (Denzer & Young, 2003).
Meal frequency has no influence on your TEF levels, however, meal size can! This relates back to the number of calories consumed. When you consume more calories, you are generally eating more food as well (assuming you are leading a healthy diet and not eating soley processed fats). Your body must work harder to break down these different foods and store their nutrients.
While keeping TEF in mind can help you create a healthier and more calorie-conscious dietary plan, it cannot and will not be the driving force in your weight loss journey. It is much more important to focus on consuming the necessary nutrients and exercising regularly. When creating your diet plan for weight loss, focus on filling foods like grains, seeds, fruits, vegetables, and proteins. In general, diets with high amounts of proteins and carbs are the best to maximize your fat loss capabilities (Walberg et. al., 1988). These diets are highly thermogenic, so people leading these diets are spending even more energy per day!
By the Nido Lifestyle Team
Barr, S., & Wright, J. (2010). Postprandial energy expenditure in whole-food and processed-food meals: Implications for daily energy expenditure. Food & Nutrition Research, 54(1), 5144. doi:10.3402/fnr.v54i0.5144
Denzer, C. M., & Young, J. C. (2003). The Effect of Resistance Exercise on the Thermic Effect of Food. International Journal of Sport Nutrition and Exercise Metabolism, 13(3), 396-402. doi:10.1123/ijsnem.13.3.396
Glickman, N., Mitchell, H. H., Lambert, E. H., & Keeton, R. W. (1948). The Total Specific Dynamic Action of High-Protein and High-Carbohydrate Diets on Human Subjects. The Journal of Nutrition, 36(1). doi:10.1093/jn/36.1.npa
Tappy, L. (1996). Thermic effect of food and sympathetic nervous system activity in humans. Reproduction Nutrition Development, 36(4), 391-397. doi:10.1051/rnd:19960405
Walberg, J., Leidy, M., Sturgill, D., Hinkle, D., Ritchey, S., & Sebolt, D. (1988). Macronutrient Content of a Hypoenergy Diet Affects Nitrogen Retention and Muscle Function in Weight Lifters. International Journal of Sports Medicine, 09(04), 261-266. doi:10.1055/s-2007-1025018