Final answer:
Infants have a higher proportion of body water, mainly due to their larger extracellular fluid compartment. By age two, the water distribution patterns align with those of adults, and during adolescence, females often have lower body water content due to increased fat accumulation.
Step-by-step explanation:
Human body water content differs significantly throughout various stages of life, exhibiting considerable changes from infancy to adulthood and into old age. Infants have about 75% of their body mass as water, a higher percentage than in adults, who have about 50-60%, with elderly adults potentially having as low as 45%.
The higher water content in infants reflects greater water proportion in the extracellular fluid (ECF) compartment. Moreover, different concentrations of solutes found in the intracellular fluid (ICF) affect water distribution within the body. By the age of two, the adult pattern of water distribution becomes apparent, with gradual shifts occurring as the body matures, including during adolescence, when females often exhibit a lower body water content compared to males due to increased adipose tissue accumulation.
The importance of maintaining a balance of solutes inside and outside cells is critical for preventing issues such as cells becoming too concentrated with solutes or bursting from excess water intake.