Body composition reference charts for UK infants and children aged 6 weeks to 5 years based on measurement of total body water by isotope dilution.

These reference data will enhance the ability of clinicians to assess and monitor body composition and FFM/FM accretion in clinical practice in younger age groups. Total body water can be measured in most patients, though abnormalities of hydration must be addressed. However, the centiles do not overlap exactly with those published for older age groups, limiting comparability between younger and older children.