Clinical Nutritionist Practice Test

The primary source of energy for the brain is glucose. The brain has a high metabolic demand, requiring a constant supply of energy to function effectively. Glucose, a simple sugar, is crucial because it can be rapidly utilized by brain cells (neurons) for immediate energy needs. While the brain can adapt to use ketone bodies (produced from fats) during prolonged fasting or carbohydrate restriction, glucose is the preferred and most immediate source of energy under normal dietary conditions. Additionally, the brain relies on a steady supply of glucose from the bloodstream, which is often derived from dietary carbohydrates. Proteins and vitamins play essential roles in the body, but they are not primary energy sources for brain function. Proteins are mainly involved in building and repairing tissues; vitamins serve as co-factors in biochemical reactions but do not provide energy directly.