Among the nutrient classes, which provides the body’s primary energy?

• A. Vitamins
• B. Minerals
• C. Carbohydrates
• D. Proteins

Answer: (C)

Carbohydrates provide the body's main energy because they can be turned quickly into glucose, the fuel cells use for most activities, especially the brain and red blood cells. This makes them the readily available source of energy for everyday work and high-intensity activities. Each gram of carbohydrate yields about 4 kilocalories, similar to protein, while fats deliver more energy per gram but are metabolized more slowly and require more oxygen, so they’re favored during longer, lower-intensity efforts. Proteins are primarily for building and repairing tissues and only serve as an energy source when carbohydrate and fat supplies are insufficient. Vitamins and minerals don’t supply calories but support the processes that convert nutrients into usable energy.