Abstract
Gut hormones are known to play an important role in long-term weight loss maintenance
after bariatric surgery. However, the interplay between gut hormones and diet-induced
weight changes remains unclear. Our aims were to evaluate the alterations of gut hormones
in diet-induced weight loss, weight maintenance, and weight regain periods. Available
studies were searched on MEDLINE, EMASE, ClinicalTrials.gov, the Cochrane Library,
and Web of science from inception to October 2016. After selection, 16 studies with
656 participants were included. Based on current evidence, we found significant alterations
of gut hormones induced by different diets. In weight-loss diets, decreased fasting
total PYY, GLP-1, CCK, GIP, PP, and amylin along with increased ghrelin levels were
observed in most studies. After weight loss, the persistent decreases of fasting total
PYY and GLP-1 levels as well as increased appetite were reported, suggesting the profound
impact of altered gut hormones on later weight regain after dietary intervention.
The differences between diet-induced changes in gut hormones and other treatments
such as bariatric surgery and exercise are also discussed in this review. Although
significant alterations of gut hormones were found during weight changes, huge heterogeneity
exists in methods and populations. More large-scale studies with elaborate design
addressing the gut hormone alterations in dietary weight regulation are required in
the future.
Key words
gut hormones - body weight changes - appetite - gut-brain axis