Adjustment of gut hormones release pattern following a fixed mealtime change in human.

Background: Gut hormones secretion is related to habitual mealtimes. However, how fast gut hormones adjust to that change when people change their fixed mealtime remains unknown.
Methods: Seven healthy male volunteers were asked to eat a test breakfast at 0700 am for 2 weeks before the start of the study. Then, their fixed mealtime was intentionally changed from 0700 am to 0900 am for next 2 weeks. Blood samples were drawn every half hour from 0500 am until next 3h after breakfast for determining gut hormone levels every week.
Results: After a change in fixed mealtime, the release pattern of acylated ghrelin was first adjusted identically according to the change and then total ghrelin was made. The meal-related fluctuations of acylated ghrelin were delayed by 120 min from week 1 after the change, while those of total ghrelin were delayed by 60 min at week 1, by 120 min at week 2. Two weeks was not enough time to adjust completely for PYY(3-36) to the change.
Conclusion: Two weeks is enough time until the pattern release of ghrelin, but not PYY(3-36) , is adjusted fully after a fixed mealtime change in human.
(Copyright © 2012 Elsevier B.V. All rights reserved.)