Serum BDNF concentrations differed significantly (p < 0.001) between participants with obesity (mean ± SD; 24,276 ± 5,425 pg/mL) and those with normal BMI (mean ± SD; 18,009 ± 7,495 pg/mL). Here, BDNF is linked to obesity due to melanocortin 4 receptor deficiency.