Which nutrient yields 4 kcal/g of energy?

The correct answer highlights that both carbohydrates and proteins provide 4 kcal/g of energy. This is a significant aspect of macronutrient metabolism.

Carbohydrates are primarily used as a quick source of energy. When consumed, carbohydrates are broken down into glucose, which the body can then readily use for energy production. This efficiency in energy production is crucial for many bodily functions, especially during physical activity.

Proteins, on the other hand, are typically known for their role in building and repairing tissues, as well as serving various functional roles like enzymes and hormones. While they can also be utilized for energy, especially when carbohydrate sources are scarce, they yield the same amount of energy as carbohydrates when metabolized—4 kcal/g.

This knowledge is key in nutritional science and diet planning, as it allows individuals to understand how different macronutrients contribute to their overall caloric intake and energy distribution.