Regional body fat distribution in New Zealand girls aged 4-16 years: A cross-sectional study by dual energy X-ray absorptiometry

OBJECTIVE: To measure total body fat content and its regional distribution within the body (head, arms, legs and trunk) in young girls and adolescents in relation to age and body mass index (BMI). DESIGN: Cross-sectional observational study. SUBJECTS: 196 healthy Caucasian girls aged 4-16 years living in an urban town in the South Island of New Zealand. MEASUREMENTS: Body weight, height and BMI. Total body fat mass (kg) and the regional distribution of this fat (measured by dual energy X-ray absorptiometry). RESULTS: All the measured variables, including total and % fat mass were higher in older age groups. Regional distribution of fat differed, with older girls having a higher proportion of their body fat in the trunk and a smaller proportion of their body fat in the head than younger girls. BMI was positively correlated with % trunk fat (r = 0.700) and negatively correlated with % leg fat (r = -0.465), Girls with higher levels of adiposity (> 75th percentile for BMI) stored more fat in the trunk and correspondingly less in the legs than girls with lower adiposity (less than or equal to 75th percentile for BMI) at five of the six age groups (P < 0.05). CONCLUSION: It is concluded that body fat mass increases and shows a more central distribution in young girls as they grow older. Increasing adiposity as determined by BMI is associated with an increase in fat deposition in the trunk and a decrease in the legs.