What are the Atwater factors for macronutrients?

The Atwater factors provide a way to estimate the caloric content of macronutrients, which is fundamental for nutrition and dietary planning. Each macronutrient has a specific number of calories per gram, which helps in calculating the energy contribution of foods in the diet.

For protein, the Atwater factor is set at 4 kcal per gram, which means that each gram of protein consumed provides 4 calories of energy. Similarly, carbohydrates also provide 4 kcal per gram. This is significant when understanding energy balance and nutrition, as both protein and carbohydrates have similar caloric values.

Fat, on the other hand, has a higher caloric content, providing 9 kcal per gram. This distinction is important because it highlights how fats are more energy-dense compared to proteins and carbohydrates.

Thus, the correct answer accurately reflects these established Atwater factors: protein at 4 kcal/g, fat at 9 kcal/g, and carbohydrates at 4 kcal/g. This knowledge is essential for anyone involved in nutrition, exercise science, or health-related fields, as it aids in making informed dietary choices and understanding the energy content of various foods.