Epidemic obesity: are genetic factors involved via increased rates of assortative mating?

• Published in: International Journal of Obesity 2002-08, Vol.26, p.S67-S67
• Main Authors: Hebebrand, J, Wulftange, H, Geller, F, Hinney, A
• Format: Article
• Language: English
• ISSN: 0307-0565

Prevalence rates of obesity have increased in several countries over the past decades. We hypothesise that genetic factors might contribute to epidemic obesity via an increased rate of assortative mating between obese individuals. We analysed deduced rates of assortative mating among parents of extremely obese children and adolescents, who belonged to two different large study groups (n=201; n=270). For this purpose we calculated parental BMI based on a) measured current heights and weights, b) self-reported current heights and weights and finally c) measured current height and recalled weights at ages 20 and 30, respectively. BMI-centiles were determined which in turn were attributed to the respective BMI-decile. Deduced rates of assortative mating were evaluated in bivariate histograms of the paternal and maternal BMI-deciles. High rates of assortative mating were observed: In the first study group almost 35% of the parental pairs had a BMI in the tenth decile; over 50% of the mothers and fathers had a BMI in the top decile. Recalled parental BMIs at ages 20 and 30 also clustered in the upper decile. These results were basically replicated in the second study group. Our results are consistent with the hypothesis that an increased rate of assortative mating has contributed to the recent rise in obesity rates, potentially via genetic mechanisms. We speculate that the recent upsurge in social stigmatisation of obese individuals underlies the hypothesized increase in assortative mating.