“Convincing evidence exists that protein exerts an increased thermic effect when compared to fat and carbohydrate. Evidence is also convincing that higher protein diets increase satiety when compared to low protein diets.” – Department of Nutrition, Harvard School of Public Health 1
1. A Calorie is not a calorie
We’ve all heard “it takes more calories to digest celery than the food actually contains”. This is talking about the “Thermic Effect of Food” – How much energy it takes to digest and process food. If our bodies are very efficient at the process then it will have a low thermic energy – so the majority of the calories we put in to our mouth are then available for energy or storing as body fat when excess energy is not required. Proteins have a high thermic effect, carbohydrates have a low thermic effect as shown below.
Let us look at the process from eating food to storing body fat of 300 calories of pure protein and 300 calories of pure carbohydrate:
More information if you hover over each step and click to get published research
2. Proteins keep us feeling fuller than Carbs
Some fascinating trials have been conducted to observe how different diets affect how hungry we feel.
References and credits:
1 The Effects of High Protein Diets on Thermogenesis, Satiety and Weight Loss: A Critical Review – Halton TL, Hu FB – Journal of the American College of Nutrition, Vol. 23, No. 5, 373–385 (2004)