Which group of people generally has the highest percentage of body water?

Infants generally have the highest percentage of body water compared to other age groups. This is primarily because they are composed of a higher proportion of fluid relative to their total body weight, with estimates indicating that newborns can be as much as 75-78% water. As children grow and develop, their body composition changes, leading to a decrease in the percentage of water.

During the early stages of life, infants also have a higher metabolic rate, which further emphasizes the importance of hydration in their growth and development. In contrast, older adults typically experience a decrease in body water percentage due to physiological changes such as loss of lean body mass and the body’s reduced ability to retain fluids. Teenagers and middle-aged adults fall in between these two extremes, generally having lower percentages of body water than infants but higher than older adults. Thus, infants distinguish themselves as the group with the highest body water content.