Similarly, in another study using high-fat diet (HFD)-treated (APP/PS1) transgenic mice, leptin failed to suppress the food intake of HFD APP/PS1 transgenic mice, suggesting impaired signalling of leptin in the hypothalamus, but hyperphagia and aggravated obesity were caused before the presence of amyloid pathology [142]. This evidence concerns the gene LEP and obesity due to melanocortin 4 receptor deficiency.