Which of the following best describes macronutrients?

• A. Vitamins and minerals
• B. Carbohydrates, lipids, and proteins
• C. Fiber and water
• D. Electrolytes

Answer: (B)

Macronutrients are the nutrients needed in larger amounts to supply energy and to build and repair body tissues. The three main macronutrients are carbohydrates, lipids (fats), and proteins. They provide calories that fuel daily activities and support growth and maintenance: carbohydrates and proteins deliver about 4 kcal per gram, while fats provide about 9 kcal per gram. The other options describe micronutrients or non-energy contributors: vitamins and minerals are required in smaller amounts for metabolic processes; fiber and water aren’t energy-providing macronutrients (fiber is a non-digestible carbohydrate, and water has no caloric energy); electrolytes are minerals important for fluid balance and nerve function but do not supply energy. So the best description of macronutrients is carbohydrates, lipids, and proteins.