LEP and obesity due to melanocortin 4 receptor deficiency: In accordance with previous studies in mice and rats (Muller-Fielitz et al., 2011; Miesel et al., 2012; Muller-Fielitz et al., 2012; Muller-Fielitz et al., 2014; Muller-Fielitz et al., 2015; Schuchard et al., 2015; Schuster et al., 2018; Winkler et al., 2018; Gustaityte et al., 2019; Rawish et al., 2020; Huber et al., 2021), we were able to show here that, on the one hand, HFD feeding leads to the development of obesity, leptin and insulin resistance, as well as hyperlipidemia, while on the other hand, treatment with TEL can prevent these scenarios.