How many calories are in one gram of protein?

One gram of protein provides four calories. This is a fundamental concept in nutrition and is part of the macronutrient composition that fuels the body. Each macronutrient has a specific caloric value: carbohydrates and protein each contain four calories per gram, while fat contributes nine calories per gram. Understanding this caloric value is essential for developing meal plans and calculating total energy intake, crucial for anyone involved in nutrition and training, such as personal trainers.

The other options reflect incorrect values for macronutrient energy content. Seven calories and two calories do not align with established nutritional science, while nine calories is the correct value for fat rather than protein. This knowledge helps fitness professionals guide clients in understanding their dietary needs, supporting weight management or muscle gain goals effectively.