How many calories are provided by one gram of protein?

One gram of protein provides 4 calories. This value is widely recognized in nutrition as it reflects the energy released during the metabolism of proteins in the body. Proteins, composed of amino acids, are essential macronutrients that serve various functions, including building and repairing tissues, making enzymes and hormones, and supporting immune function.

When the body breaks down protein, it processes these amino acids to create energy, which is quantified at 4 calories per gram. This is an important aspect of dietary planning and understanding macronutrient contributions to overall caloric intake. Carbohydrates also yield 4 calories per gram, while fats offer 9 calories per gram and alcohol provides 7 calories per gram. This knowledge is fundamental for calculating macronutrient distributions in meal planning and for understanding energy balance in nutrition.