How many calories does 1 gram of protein yield?

One gram of protein yields 4 calories. This is a foundational principle in nutrition that pertains to the energy content of macronutrients. Proteins are made up of amino acids, which are crucial for various bodily functions, including muscle repair, hormone production, and enzymatic reactions. The caloric value is determined by the energy released when the body metabolizes these amino acids.

When understanding the energy contributions of different macronutrients, we see that carbohydrates also yield 4 calories per gram, while fats yield 9 calories per gram. This differentiation is essential for anyone studying nutrition, dietetics, or exercise training, as the caloric content of macronutrients plays a significant role in dietary planning and understanding energy balance in the body.