The manuscript by Behary et al provided a nice demonstration that postprandial gut hormones at the level comparable to those after RYGB, while sufficient to reduce overall energy intake providing benefits on glycaemia and body weight, do not explain the changes in food preference or sweet taste perception often seen with the latter.

These findings, although did not support the hypothesis, represent new and important insights in the area.

Eating behaviour is regulated by both hedonic and homeostasis mechanisms.

The authors discussed the potential relevance of body weight/fat and leptin to their findings, which in this reviewer's point of view is likely to be the key to explaining the findings.

Would it be possible to measure leptin levels in the GOP cohort and compare them with RYGP patients?

The manuscript otherwise is well written.