In general, foods are made up of carbohydrates, proteins, and fats, each of which provide a different number of calories: 1  Carbohydrates provide 4 calories per gram. 2  Proteins provide 4 calories per gram. 3  Fats provide 9 calories per gram.
Importance of Water. Water is used for various important purposes: Water in Agriculture. Water plays the most important role in agriculture. Agriculture is impossible without irrigation throughout the crop season. Irrigation ensures proper plant growth.
Quick Answer. Water is important because the human body has a drought management system that prevents dehydration and water is the most crucial part of that system. Water also helps regulate body temperature, serves as a lubricant and is a natural headache remedy (headaches can be a sign of dehydration). Continue Reading.