2009); their adipocytes are highly sensitive to insulin action and are able to increase their lipid storage capacity in response to a high‐fat (HF) diet (Kadiri et al. 2017). These mice are protected against HF diet‐induced obesity (Lau et al. 2008) and related systemic insulin resistance (Kang et al. 2011), without harboring any liver steatosis or hyperlipidemia. Such characteristics and the fact that the physical activity of sg/sg mice is less than that of WT littermates (Akashi and Takumi 2005) begs the question of where the energy derived from the food intake is disposed of. This evidence concerns the gene INS and hydrops fetalis.