What is the primary energy source for the body's cells?

Carbohydrates are recognized as the primary energy source for the body's cells due to their efficient and rapid breakdown during metabolism. When carbohydrates are consumed, they are digested into glucose, which is used by cells for immediate energy or stored as glycogen in the liver and muscles for later use. This process is critical, especially during high-intensity exercise, where quick energy is necessary.

While fats also provide a substantial energy source, they are metabolized more slowly and are typically utilized during lower-intensity activities or prolonged exercise. Proteins, although essential for repair and growth, primarily serve other functions, such as building and repairing tissues, rather than acting as the main energy source. Lastly, vitamins are crucial for various metabolic processes but do not directly provide energy to the cells; instead, they act as coenzymes or cofactors in energy production pathways. Thus, carbohydrates are deemed the most immediate and preferred source of energy for bodily functions.