Variation in body mass index among Polish adults: effects of sex, age, birth cohort, and social class.

Variation in the body mass index (BMI) among occupationally active inhabitants of one Polish urban center was studied by means of a three-factor ANOVA. The material is cross-sectional and comprises 32,750 men and women aged 22-60 years, examined in five successive surveys between 1983-1999. The factors considered in each sex were: 1) age category, 2) year of examination, and 3) social class. The increase of BMI with age is markedly greater among women than among men. No sustained intergeneration trend towards increased BMI was detectable in either sex. The BMI means rise regularly with decreasing position on the social scale in both sexes, but this effect is much more dramatic in women. The latter finding suggests that the condition of being situated low on the social scale is conducive to growth of fatness with age, markedly more so in women than in men. The absence of a secular trend in BMI means during the period considered contrasts with results reported for a number of other countries. This finding is intriguing, because Poland underwent abrupt and profound socio-economic transformation in the early 1990s. Copyright 2001 Wiley-Liss, Inc.