Underweight and overweight cases among the mentally retarded.

The body mass index (BMI) was calculated at the age of 20 for all the 132 survivors (83%) out of the 159 mentally retarded individuals born in 1966 in Northern Finland. Reliable information was acquired for 112 cases (84.8%). The mean BMI for these cases did not deviate significantly from that for an average Finnish population at age 20-29 years. It was found that 41.5% of the slightly retarded cases (IQ 35-70) and 28.6% of the seriously retarded ones (IQ less than 35) were of ideal weight (BMI 20-24), while 9.8% of all the retarded individuals were moderately obese (BMI greater than 30) and 7.1% seriously so (BMI greater than or equal to 32). Ninety-one per cent of the seriously obese cases lived with their parents and did not participate in any occupational therapy or work. A total of 29.5% of the mentally retarded subjects were underweight (BMI less than 20), a condition which would seem to be above all a problem for seriously retarded individuals and an obvious consequence of the different feeding and dietary problems connected with their multiple disabilities.