Postnatal development of adipose tissue in normal children on strictly controlled calorie intake.

The relations between adipose tissue development at birth, later expansion of fat mass and the behavior of fat mass and fat cell growth from birth to 12 mo of age have been studied in normal children born to normal, obese or diabetic mothers and maintained on strictly controlled calorie intake. A simple method for fat cell size determination on microsamples of fat tissue, specifically designed for small children, is reported. In the first 3 mo of life, a marked increase of fatty tissue from 13.4 +/- 0.4 to 20.3 +/- 0.8 percent of total body mass was observed. Subsequently, a sharp decrease in the relative amount of fat mass occurs, probably related to an increased energy expenditure or to a slightly higher protein content in the diet. No sex related differences in body weight, body fat mass, sum of skinfold thickness or fat cell weight were found throughout the study. No significant differences in body fat mass, sum of skinfold thickness and body fat mass as percent of body weight was observed at birth and at 3 or 6 mo of age in children of obese or gestational diabetic mothers, in comparison with children of normal mothers, and no significant correlation was found between maternal adiposity (sum of skinfold thickness or pre-gravidic overweight) or glucose tolerance (blood glucose area after OGTT) and adipose tissue development in the first 6 mo of life. Thus, in children on strictly controlled intake, obesity or diabetes in the mother do not relate to the rate of fat accumulation. Moreover, no relations were found between adipose tissue development at birth and subsequent rate of fat enlargement in the first year of life. Thus, when the interference of a different calorie intake is excluded, adiposity at birth has no predictive value for possible fatness later in infancy.