Which nutrient is critical for energy metabolism?

Carbohydrates are essential for energy metabolism because they are the body's primary source of fuel. When consumed, carbohydrates are broken down into glucose, which can then be utilized immediately for energy or stored in the liver and muscles as glycogen for later use. This process is especially important during high-intensity physical activities, where quick energy is needed.

In addition to serving as a rapid source of energy, carbohydrates also play a vital role in sparing protein from being used as an energy source, allowing it to be available for its primary functions like tissue repair and growth. While fats and proteins also contribute to energy metabolism, carbohydrates are often the preferred energy source, particularly in settings of intense exercise. Fiber, while beneficial for digestive health, does not contribute directly to energy metabolism in the same way that carbohydrates, proteins, and fats do.