Relationship between morbidity and extreme values of body mass index in adolescents

Although the association between overweight and cardiovascular risk factors is well documented in cross-sectional and longitudinal studies, reports of adolescent morbidity associated with underweight in industrialized countries are rare.

This population-based study includes approximately 110,000 17 year old Israeli Jewish males who underwent routine physical examination at army induction centres. Computerized data tapes include overall health profiles, specification of physical and mental conditions, and height and weight measurements. Medically significant conditions are those with sufficient severity to preclude service in a combat unit.

Functional limitation is more prevalent at both extremes of the body mass index (BMI) distribution: 149.5/1000 among severely underweight individuals and 164.3/1000 among severely overweight subjects. Overweight was associated with hypertension (14.9/1000 among the severely overweight), as well as joint conditions of the lower extremities, mainly hip, ankle and knee disorders. Functional disorders associated with underweight are bronchial and lung conditions, including asthma (14.2 and 18.9/1000 in the mildly and severely underweight), scoliosis, intestinal conditions and emotional disorders (mainly neurosis).

Both under- and overweight are associated with morbidity at age 17. Intervention programmes should begin at an early age.