The thermic effect of food (TEF) is the amount of energy it takes for your body to digest, absorb, and metabolize the food you eat. TEF makes up a part of your daily calorie expenditure ... think calories out ...
You can see in the chart above, PROTEIN is the macronutrient with the highest thermic effect. Research shows that protein-rich foods boost your metabolic rate by 15-30%, compared to 5-10% for carbohydrates and 0-3% for fats.
Beyond the TEF protein offers as a macronutrient, another metabolic-boosting property is the fact that PROTEIN helps build muscle mass, and muscle mass requires far more energy to maintain. PROTEIN also has a high satiety factor, meaning it helps you stay full for longer, which can help control appetite and curb cravings. Also many protein foods like fish, eggs and grass fed beef are nutrient dense, making protein the most nourishing macronutrient.
Here is a study that found when people are allowed to eat as much as they desire on a diet that consists of 30% protein, they ended up consuming 441 fewer calories per day compared to eating only 10% protein.
Eating a breakfast high in protein increases satiety and reduces the calorie intake of subsequent meals compared to a breakfast made up of cereal or bagel. The same is seen at lunch. Many get enough protein in their dinner, but it is often these other meals and even snacks that are lacking enough protein to have a satiating effect on appetite as well as all the other benefits mentioned above.
It is also important to be aware that different foods (and the calories they provide) have different effects on our hormones, satiety, fat storing genes, burning calorie genes, metabolic rate, gut health and a lot more. Therefore, all calories are not created equal.
For example, if you eat 500 calories from donuts you should not expect the same weight loss as eating 500 calories of chicken breast or 500 calories of broccoli. A single donut can be up to 500 calories and can be relatively easy to do, especially due to its hyper-palatable taste. 500 calories of broccoli is equivalent to 9 cups of broccoli, which would be very hard to do and has a completely different TEF than donuts and it’s higher in fiber, which results in a much larger proportion of the calories from broccoli being used for digestion. The same is true for 500 calories of chicken. When you get a large portion of your daily calories from protein, you’re going to be burning 20-30% simply by digesting it, which helps to create a calorie deficit. Therefore eating 500 calories of chicken is more like 350-400 calories because of protein’s TEF.
The key take away is, if you want to lose weight, maintain weight, or build muscle, you should incorporate protein into every meal. Your body will thank you for it!