What comprises about 60% of the body's weight?

Water comprises about 60% of the body's weight, making it a critical component of human physiology. This significant percentage highlights the essential role water plays in various bodily functions, including temperature regulation, nutrient transport, and waste elimination. It also serves as a solvent in many biochemical reactions, facilitating metabolism and other vital processes.

In contrast, proteins, fats, and carbohydrates each contribute to body weight, but to a lesser extent. While proteins are essential for building and repairing tissues, fats are a major energy store and play roles in cell structure and hormone production, carbohydrates primarily serve as a quick energy source and are found in various proportions throughout the body's tissues. However, none of these macronutrients reaches the same level of representation in body weight as water.