BDNF and obesity due to melanocortin 4 receptor deficiency: BDNF is also associated with energy homeostasis.[27] It has been reported that high fasting serum BDNF concentrations were observed in women with obesity.[28, 29] Furthermore, circulating BDNF also positively correlated with the risk factors of metabolic syndrome.[29, 30] However, a contrary finding has also been reported wherein fasting BDNF concentrations were decreased in subjects with obesity upon cross-sectional assessment.[31] Thus, the relationship between obesity and fasting BDNF remains largely controversial.[32]