Considering the relationship of the observed GLP‐1 cell hyperplasia in obesity and the incretin response, it is quite unexpected that the numbers of duodenal GLP‐1 expressing cells correlated positively with markers of dysglycemia including HbA1C concentration (Figure 6) and poor glucose tolerance during the meal test. This evidence concerns the gene GCG and obesity due to melanocortin 4 receptor deficiency.