GFRAL and obesity due to melanocortin 4 receptor deficiency: Similarly, genetic overexpression of Gdf15 results in decreased body weight and increased resistance to obesity associated with high-fat diets, whereas Gdf15 and Gfral deficient mice are more susceptible to diet-induced obesity (Mullican et al., 2017; O’Rahilly, 2017; Tran et al., 2018).