BDNF and obesity due to melanocortin 4 receptor deficiency: On the other hand, Plaza-Florido et al. [21] and Rodríguez-Ayllón et al. [22]—both with longer, 20-week multicomponent interventions in children with overweight/obesity—reported no changes in BDNF levels after exercise (p > 0.05), nor any genotype × intervention interaction (in the case of Plaza-Florido et al. [21]).