Obesity was also accompanied by hyperinsulinemia of both genotypes at the ages of 6 and 10 months; in addition, 10-month-old APP/PS1 mice on a HFD reached insulin levels that were 38-fold higher than those of their controls on a STD and 3-fold higher than those of age-matched WT controls on a HFD (Table 1). This evidence concerns the gene APP and obesity due to melanocortin 4 receptor deficiency.