Multigenerational transmission of obesity: A systematic review and meta-analysis

There is a strong link between parental and offspring obesity status. However, the state of epidemiological evidence on multigenerational transmission of overweight/obesity, such as from grandparents to grandchildren, is relatively unknown. This systematic review collates and appraises existing evidence on multigenerational transmission of overweight/obesity and uses meta-analytic estimates for quantitative synthesis. Six electronic databases were searched for publications reporting the relationship between grandparents and their grandchildren overweight/obesity status. A total of 25 studies from 17 countries with a combined population of 238,771 study participants met the inclusion criteria. About 60% (15) of the reviewed studies reported a positive association between grandparent-grandchild (GP-GC) overweight/obesity, out of which 11 were statistically significant. Seven studies reported odds ratios of GP-GC overweight/obesity associations and were included in the meta-analysis. The pooled estimates showed a significant GP-GC association in overweight/obesity status (odds ratio [OR]: 1.79, 95% confidence interval [CI]: 1.01-2.57). Thus, the current research evidence shows that grandchildren's overweight/obesity status is associated with their grandparents' overweight/obesity status, indicating a multigenerational transmission of obesity. However, more studies, especially from developing countries, are required to assess the robustness of these findings. Future studies should also focus on the mechanisms through which this transmission occurs