What is a concentrated source of energy than carbohydrates?

A concentrated source of energy that is more efficient than carbohydrates is fats. Fats provide approximately 9 calories per gram, compared to carbohydrates, which offer about 4 calories per gram. This higher energy density makes fats a vital energy reserve for the body, especially during prolonged physical activity or periods of fasting. Additionally, fats play essential roles in hormone production and cellular structure.