In 7 days, the water in an adult body accounts for about 60-70% of the total weight. Generally, the younger and fatter, the greater the proportion of water. For example, a baby weighing 5 kilograms accounts for more than 4 kilograms. Of course, there are obvious differences in water content in different parts of the human body. For example, bones only contain 16-46% water, while muscles contain more than 70%. As for plasma and cerebrospinal fluid, the proportion of water is above 90%. The distribution of water in human body is uneven, about 40% is in cells, 20% is between tissues and 5% is in blood. Therefore, life and water are inextricably linked.