FACTORS ASSOCIATED WITH WEIGHT-FOR-HEIGHT AND SKINFOLD THICKNESS IN BRITISH CHILDREN

Study objective - To examine the associations of social and biological factors with measures of obesity in children. Design - The study had a cross sectional design. Setting - The analyses were based on data fr om two national study of health and growth cross sectional surveys. Th e ''representative sample'' comprised 1990 data from 22 English areas and 1990-91 data from 14 Scottish areas; the ''inner city sample'' com prised 1991 data from 20 English areas. Participants - The subjects we re primary school children aged mainly 5-11 years living in England an d Scotland. The ''representative'' sample included 10 628 children - 6 463 living in England and 4165 living in Scotland. The ''inner city'' sample included 7049 children - 2183 white, 1124 Afro-Caribbean, 2696 Indian subcontinent, and 1046 from other groups. Due to missing values on continuous variables, 8374 children were included in the analyses. Measurements and main results - The relation between social environme nt and childhood overweight was studied using several indicators of ob esity. Triceps, subscapular, the sum of triceps and subscapular skinfo lds, and weight for height were used as dependent variables. The analy ses were carried out in two stages. Firstly, multiple linear regressio n analyses were used to assess the factors associated with dependent v ariables treated as continuous. Secondly, multiple linear logistic reg ression analyses were used to examine the association between independ ent factors and overweight and fatness defined as binary variables. Bi rth weight, mother's body mass index (BMI), and father's BMI were cons istently associated (p < 0.001) in all models and were the variables t hat contributed most to the explained variation in the dependent varia bles. In the multiple regression analyses there was a consistent inter action between the effects of ethnic origin and family size on each ou tcome variable. In the logistic regression analyses the interaction wa s not significant, and highly significant associations between both ov erweight and fatness with the number of children were shown. Ethnic gr oup was not significantly associated with overweight but it was with f atness. The strengths of the remaining significant associations were s light and inconsistent inrelation to the dependent variables or the ty pe of analysis. Conclusion - Very few variables were associated with m easures of overweight and fatness. The only useful factor that was hig hly associated with all measures of fatness was the parents' BMI. Stra tegies to prevent childhood obesity should be aimed at the total popul ation and special emphasis should be placed on families in which one o r both parents are overweight.