Which of the following is not classified as a macronutrient?

The classification of macronutrients includes carbohydrates, proteins, and fats, which are essential for providing energy and supporting bodily functions. Macronutrients are nutrients that the body requires in larger amounts and are fundamental for growth, metabolism, and other physiological processes.

Alcohol, while it does provide calories and can impact metabolism, is classified as a psychoactive substance rather than a macronutrient. It is metabolized differently in the body and is not essential for human health. Unlike the other three macronutrients that play vital roles in energy production and overall health, alcohol's primary impact is often as a recreational substance, which categorizes it separately from the essential macronutrients that are critical for nutritional needs. Therefore, identifying alcohol as not a macronutrient aligns with the foundational understanding of nutrition and its components.