APP and obesity due to melanocortin 4 receptor deficiency: Similarly, a strong association between weight loss and decreased levels of cerebral Aβ plaques has been reported using several dietary regimens including ketogenic and calorie-restricted diets (Patel et al., 2005; Van der Auwera et al., 2005; Wang et al., 2005; Halagappa et al., 2007; Mouton et al., 2009) in different APP transgenic strains, providing evidence that body weight, diet, and obesity are important modulators of Aβ pathology.