THE INCIDENCE OF OBESITY IN THE MENTALLY RETARDED CHILDREN

Abstract

In order to clarify the incidence of obesity in mentally retarded children, a cross-sectional survey of standing height, body weight, Rohrer's index and skinfold thickness was carried out on 443 institutionalized mentally retarded boys and 250 girls from 9 to 16 years of age from 1979 to 1981. The intellectually normal subjects as the controlled group were 339 boys and 302 girls from Toyama city, and Japanese children measured by the Ministry of Education in 1979. Individuals were classified (1) as obese (above 160) and semi-obese (above 145) according to Rohrer's index, (2) as obesity oriented (120% above the average weight for their sex, age and height) on the basis of standard weight tables by the Ministry of Education in Japan, and (3) as slightly, fairly and seriously obese based on total skinfold thickness in the upper arm and scapular sites as described by Dr. Nagamine. The following major results were found: 1) The total incidences of semi-obesity and obesity classified by Rohrer's index were 5% - 19% and 14%-52% in the mentally retarded groups, and 3%-15% and 0%-16% in the controlled groups, for males and females respectively, aged 9 to 16 years. 2) In the mentally retarded groups, the incidences of obesity orientation were 17%, 16%, 9%, 10%, 7%, 14% in males and 11%, 22%, 25%, 31%, 19%, 14% in females. In the national survey, obesity orientation was 6% to 7% in both sexes, aged 9 to 14 years. 3) The total incidences of slight, fair and serious obesity classified by Dr. Nagamine's skinfold thickness method were 28%, 42%, 33%, 28%, 27%, 26%, 14%, 11% in the mentally retarded boys and 16%, 5%, 23%, 11%, 18%, 10%, 10%, 17% in the controlled groups for boys, aged 9 to 16 years. In the 9 to 16 year-old girls, they were 9%, 35%, 25%, 32%, 34%, 35%, 37%, 29% in the mentally retarded groups and 8%, 9%, 3%, 13%, 8%, 20%, 16%, 2% in the controlled groups. These results suggest that there is a high incidence of obesity in mentally retarded children.