ADIPOSITY IN CZECH CHILDREN FOLLOWED FROM 1 MONTH OF AGE TO ADULTHOOD - ANALYSIS OF INDIVIDUAL BMI PATTERNS

In Czechoslovakia, overweight and nutrition-associated pathologies are frequent. The body mass index (BMI) is often used in the clinical assessment of adiposity in children and adults. Its variations during growth are well documented. A cohort of 300 newborns were selected at random in Prague between 1956 and 1960. Weight and height were collected in these subjects at the ages of 3, 6, 9, and 12 months and twice a year from 1 to 20 years. Charts of longitudinal variations of the BMI were drawn for males and females. The three expected phases of BMI development were observed: initial rise until 12 months, subsequent decrease, and second augmentation (the 'adiposity rebound', 'AR') between 4 and 8 years of age. The inverse relationship between age at AR and the BMI in adulthood was confirmed: in the leanest adults, AR had happened by age 7-6 years, in the heaviest adults, age at AR was around 5 years. Many lean (44%) and fat (58%) infants developed into average-size adults. The risk of becoming a heavy adult was increased in fat infants (31%) as opposed to non-fat (22%) ones. The relative risk of fat infants to become obese adults as compared to non-fat infants is 31/22 = 1.8. Individual growth curves of children with very high or very low adult BMI values illustrate the relationships between BMI at 12 months, age at AR and adult BMI. The Czech BMI distribution was higher than a comparable French one at all percentiles after age 7 years. Although differences in body frame could account for some of the difference, increased body fat accumulation could start early in many young Czechs. Nutritional data should be collected in order to identify the factors responsible for the high BMI level in Czech children and adults.