Figure 7. Graphs illustrating two possible causal pathways to explain associations of the BMI allele score with the outcomes.

Abbreviations: BMI, body mass index. Left graph represents the intended pathway we have investigated, where the BMI allele score is an IV for BMI and the variants affect the outcome solely through observed BMI in childhood. The right graph represents the alternative causal pathway, where the allelic score affects BMI indirectly through the outcome variable. It is possible that these two pathways both occur for a given outcome, such that the graph would become cyclical.