FGF21 and Obesity: It has recently been shown that the anti-diabetic effectof FGF21 in genetically obese mice (ob/ob and Ay mice) appearsonly in males (Berglund et al., 2009; Makarova et al.,2020; Makarova et al., 2021b), whereas in mice with obesitycaused by HFD it is manifested both in females and males.In mice with SFD-induced obesity (SFDIO), the effects ofFGF21 have been shown in males (Coskun et al., 2008), whilein females, they have not been studied.