Overweight and anthropometric changes in adulthood: a prospective study of 17,000 Finns.

Changes in weight, body mass index (BMI), and thickness of triceps and subscapular skinfolds were studied in 17,294 adult Finns who, as part of a health survey, were examined twice after an interval of 4 to 7 (average 5.7) years. During the follow-up, the mean weight and BMI rose in men and women below the age of 50 at entry, changed little in men aged 50-70 and in women aged 50-60, and rapidly declined at later ages. Individual weight changes were generally small; about two-thirds of the participants maintained their weight within 5 kg from the initial weight. About 9 per cent of the men and 4 per cent of the women gained 10 kg or more, and 2 per cent of the men and 4 per cent of the women lost 10 kg or more in 5 years. Weight loss was associated with old age and high initial BMI, whereas weight gain was most common in the young, even in those with a high initial BMI. Young overweight subjects need most attention in prevention and treatment programmes for obesity.