you are made of fat, water, protein, carbohydrates, vitamins and minerals. When you step on a scale, on average 60 percent of your body's weight is water, 20 percent is body fat (slightly lower percentage for a man) and 20 percent is a combination of protein, carbohydrates, minerals, vitamins and other naturally produced biochemicals. A very easy way to remember this formula is to think of it as the "60-20-20" rule. 60 percent water, 20 percent fat, 20 percent protein and other nutrients.

Based on the above body percentages, you can rationally expect that the average 140 pound person's body weight would consist of about 84 pounds of water, 28 pounds of body fat and 28 pounds of protein, minerals, carbohydrates and vitamins. However these numbers are not a perfect formula and may vary from person to person. For instance, a older person would generally have less muscle and more fat than a younger person.

There are differences between men's and women's body compositions. More of a women's body weight will come from fat and more of a man's body weight will come from protein and calcium. For a man, protein crammed muscles and mineral crammed bones have denser tissue than fat. When you compare the weight of a man and women who are roughly the same size and height, the man is likely to weigh more each and every time.