Why protein burns more calories to digest

When you eat, your body spends calories just to chew, digest, absorb and store the food. This is called the thermic effect of food, or TEF. It is a small part of your daily burn, usually around 5-15% of the calories you eat. Here is the interesting part: not all foods cost the same to process. Protein is the most expensive macro for your body to handle, fat is the cheapest. So the same 100 calories from dal or eggs is not quite the same as 100 calories from ghee, once your body does the work of digesting it. This is not a magic weight-loss trick. The number is small. But it is one more honest reason a little extra protein can help when you are in a deficit, on top of keeping you full and protecting your muscle.