What nutrient has no calorie value but is essential for transporting nutrients and digestion?

Water is essential for numerous bodily functions, including the transportation of nutrients and digestion, yet it contains no calories. It plays a critical role in maintaining cellular function and is a major component of the body, accounting for a significant percentage of body weight. It aids in the digestion process by helping to dissolve nutrients so they can be absorbed by the bloodstream. Furthermore, water facilitates the elimination of waste through urine and aids in temperature regulation through sweating.

While nutrients such as proteins, carbohydrates, and fats provide energy (calories), water remains unique in that it is vital for health and physiological processes without contributing any caloric value.