While the body is at rest, what percentage of protein typically makes up energy expenditure?

In a resting state, the body uses a variety of macronutrients to meet its energy needs. Protein typically contributes to a lower percentage of overall energy expenditure compared to carbohydrates and fats. The range of 15-20% accurately reflects the role of protein in energy expenditure during rest.

At rest, the body primarily relies on fat for energy, as it is the most abundant stored macronutrient and requires less oxygen for metabolism compared to carbohydrates and proteins. However, due to the fact that proteins can be used for energy, especially during prolonged fasting or strenuous physical activity when carbohydrate stores may be low, they still account for a modest percentage of energy utilization. The 15-20% figure indicates a balanced approach where protein does contribute to energy expenditure but is not the primary source.

Other ranges would suggest a higher reliance on protein for energy, which does not align with typical metabolic pathways in a resting state. Therefore, the accurate depiction of protein's contribution as 15-20% emphasizes the body's preference for using fats as a primary fuel source while still acknowledging protein's role in energy metabolism.