What percentage of energy do carbohydrates provide at rest?

At rest, the body primarily relies on carbohydrates as a source of energy, especially for maintaining normal physiological functions and supporting brain activity. The choice indicating that carbohydrates provide about 40% of energy at rest aligns with metabolic studies showing that, although fats become a significant source of energy during prolonged low-intensity activities, carbohydrates still play a crucial role even when at rest.

This reliance on carbohydrates is particularly important due to their relatively quick availability for energy production compared to fats, especially for the brain and red blood cells, which prefer glucose as a fuel source. Therefore, the understanding that carbohydrates account for approximately 40% of energy expenditure at rest highlights the balance the body maintains between using carbohydrates and fats for sustaining everyday functions.