title: Body fat and adipose tissue cellularity in infants: a longitudinal study.
abstract: Body fat, fat cell size, and fat cell number were determined in a longitudinal study on 16 normal-weight infants during the age period 1-18 mo. The methods used included whole-body counting of 40K for determination of body fat and adipose tissue biopsies. A new method of calculation of body fat in infants is presented. No sex differences were found. Body fat expressed as per cent of body weight increased from 16.2% to 28.1%. From 1 to 12 mo of age the expansion of body fat was explained by and increase in fat cell size, while in the age period 12-18 mo it was mainly due to an increase in fat cell number. At 18 mo lthe fat cell size was the same as in 8-yr-old girls and 22-yr-old women (normal-weight females previously studied). The fat cell number at 18 mo, however, was far below the number at 8 yr of age, as well as the still higher number of the 22-yr-old women.
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology* / Q000166:cytology; D000375:Aging; D001835:Body Weight; D005110:Extracellular Space; D005260:Female; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D008954:Models, Biological; D011188:Potassium / Q000378:metabolism
chemical_list: D011188:Potassium