Which nutrient is the body's primary source of energy?

Which nutrient is the body's primary source of energy?

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

Answer: (C)

Carbohydrates provide the body's primary source of energy because they are quickly converted into glucose, which fuels the production of ATP through glycolysis and subsequent pathways. This rapid supply is especially important during most physical activities, particularly those of higher intensity. The body also stores carbohydrates as glycogen in the liver and muscles, which can be tapped into quickly during exercise. Fats, while energy-dense, are slower to mobilize and are typically used more during longer, lower-intensity activity. Proteins aren’t meant to be a main energy source; they’re best kept for tissue repair and metabolic functions and are used for energy mainly when carbohydrate supplies are very low. Vitamins don’t provide energy themselves, though they’re essential for metabolism.

Carbohydrates provide the body's primary source of energy because they are quickly converted into glucose, which fuels the production of ATP through glycolysis and subsequent pathways. This rapid supply is especially important during most physical activities, particularly those of higher intensity. The body also stores carbohydrates as glycogen in the liver and muscles, which can be tapped into quickly during exercise. Fats, while energy-dense, are slower to mobilize and are typically used more during longer, lower-intensity activity. Proteins aren’t meant to be a main energy source; they’re best kept for tissue repair and metabolic functions and are used for energy mainly when carbohydrate supplies are very low. Vitamins don’t provide energy themselves, though they’re essential for metabolism.