However, it was recently reported that an energy restriction weight loss program (without exercise) did not increase mRNA expression of NR1D1 or PER1 in adipose tissue from adults with obesity (60, 63) suggesting the significant alterations in core clock genes we observed may be at least partially mediated by a direct effect of the exercise stimulus. Here, NR1D1 is linked to obesity due to melanocortin 4 receptor deficiency.