What macronutrient serves as the primary energy source for the body?

The primary energy source for the body is carbohydrates. When consumed, carbohydrates are broken down into glucose, which is utilized by the body's cells for energy. Glucose can be immediately used or stored in the liver and muscles as glycogen for later use. In terms of energy density, carbohydrates provide about 4 calories per gram, making them a significant and efficient energy source.

While fats and proteins also provide energy, they play different roles in the body. Fats are a more concentrated source of energy, yielding about 9 calories per gram, and are primarily used during prolonged, low-intensity activities as well as for energy storage. Proteins can also be used for energy, but their primary role is to support growth, repair tissues, and facilitate various physiological functions, making them less of a direct energy source compared to carbohydrates.

Minerals, on the other hand, do not provide energy in the form of calories but are essential for a variety of biochemical reactions and functions within the body. Therefore, carbohydrates are recognized as the body's preferred and primary source of energy, especially for high-intensity physical activities.