Which of the following statements about total body water composition are correct?

C. Newborn infants have the greatest proportion of total body water.

D. Total body water decreases steadily with age. 

DISCUSSION: Since fat contains little water, lean persons with a proportionately greater muscle mass have a greater than expected volume of total body water. Likewise, the female body habitus and obesity contribute to decreased total body water percentage. The highest proportion of total body water is found in newborn infants, and total body water decreases steadily and significantly with age. The actual figure for a healthy person is remarkably constant.