In order to further reveal the causal association between different types of body anthropometric indexes of obesity and the target involved in the top five functional and pathway annotations with the highest frequency, that is, APOE gene polymorphisms, the IVW model was used in the two-sample MR analysis, and the results are shown as follows (Figure 4, Figure 5 and Figure 6). This evidence concerns the gene APOE and obesity due to melanocortin 4 receptor deficiency.