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.
You need water to digest your food and get rid of waste, too. Water is needed for digestive juices, urine (pee), and poop. And you can bet that water is the main ingredient in perspiration, also called sweat. Besides being an important part of the fluids in your body, water is needed by each cell to function normally. Your body doesn't get water only from drinking water. Any fluid you drink will contain water, but water and milk are the best choices. Lots of foods contain water, too.
Importance of Water Our Earth seems to be unique among the other known celestial bodies. It has water, which covers three-fourths of its surface and constitutes 60-70 wt % of the living world. Water regenerates and is redistributed through evaporation, making it seem endlessly renewable. So why worry?