This was despite these regions being those showing differences in post‐prandial BGU in patients post‐RYGB surgery compared to participants with obesity or normal weight controls, suggesting that the exaggerated post‐prandial GLP‐1 and PYY responses after RYGB surgery were not responsible for changes in regional BGU, though sample size was small for the post‐RYGB group (n = 9). Here, PYY is linked to obesity due to melanocortin 4 receptor deficiency.