BDNF and obesity due to melanocortin 4 receptor deficiency: Unlike previous studies that have solely relied on BMI, our study is the first to investigate the association between BDNF polymorphism and body composition using MRI, yielding a higher level of precision in quantifying fat mass and fat-free mass, noted to be a more reliable predictor of obesity-related complications than BMI-based measures (Mitra et al., 2017).