Fifteen-year changes in body mass index and waist circumference in Finnish adults

Background Obesity is an increasing health problem. Data on long-term obesity trends are most often based on the measurement of body mass index (BMI). Abdominal obesity, assessed by waist circumference may, however, be more closely related to health risks than overall obesity. The aim of this study was to investigate 15-year changes in general and abdominal obesity among adults in Finland, and furthermore, to assess whether obesity trends differ between educational groups. Design Four cross-sectional population surveys conducted at 5-year intervals between 1987 and 2002. Methods Altogether, 9025 men and 9950 women aged 25-64 years participated in these surveys. The weight, height, and waist circumferences of the participants were measured using a standardized protocol. Results Mean waist circumference increased by 2.7 cm in men and 4.3 cm in women in 15 years. Whereas the distribution of BMI values did not change much, a remarkable shift towards higher waist circumference values was observed in 15 years. In both sexes, mean and high values of waist circumference increased in all educational groups. However, the values remained highest among the subjects with the lowest education. Conclusions These results indicate that adverse changes in body shape have taken place from the late 1980s to the early 2000s. Given that one in five Finnish adults is defined as obese based on BMI, there is an even larger group of individuals at risk of obesity-related metabolic disorders because of abdominal obesity, particularly among low-educated individuals.