AHSG and obesity due to melanocortin 4 receptor deficiency: Regarding subgroup analysis, in obese individuals, physical exercise favored a reduction in fetuin-A the overall same effect was not observed in individuals with obesity (g = − 0.096; 95%CI, − 0.328 to 0.135; p = 0.415; I2 = 29.04%) and type 2 diabetes/dysglycemia (g = − 1.698; 95% CI, − 3.570 to 0.174; p = 0.075; I2 = 94.24%).