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.
Now lets take a closer look at the importance of water in our own bodies. As babies we are approximately 75 to 80% water and as we grow older this percentage decreases until the percentage is reduced to approximately 60 to 65% for men and 50 to 60% for women. The human brain is about 85% water and our bones are between 10 to 15% water. The chemical structure of water H 2 O and both the hydrogen and oxygen have great importance as life giving properties and a preserving force to our systems. Women have a higher percentage of adipose tissue than men, giving them a lower percentage of water.