A Systematic Review On The Role Of The FTO Rs9939609 Variant In Regulating Appetite In Adults

Abstract

Background: Several studies have reported that the fat mass and obesity-associated (FTO) rs9939609 polymorphism influences hunger and satiety sensations, affecting appetite. The A allele of rs9939609 is specifically associated with altered postprandial satiety levels. Carriers of the A genotype often experience lower postprandial fullness and higher postprandial appetite levels compared to TT homozygotes.

Objective: The present study aimed to evaluate the role of the rs9939609 single-nucleotide polymorphism of the FTO gene on appetite in adults through a systematic review across different populations.

Methodology: In this study, systematic review evaluated the influence of the rs9939609 single-nucleotide polymorphism of the FTO gene on appetite. Articles from Scopus, PubMed, and Google Scholar, published between 2008 and 2024, were searched. Data identification, screening, and extraction were performed as per the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses).

Result: The systematic review analyzed seven studies investigating the role of the FTO rs9939609 variant in regulating adult appetite. Important conclusions from this study are the following:

Post-Exercise Hunger: Individuals with the TT genotype may experience greater hunger and appetite after exercise than those with the AT allele.

Postprandial Responses: Weak associations were reported between the FTO rs9939609 genotype and fasting or postprandial appetite-related outcomes in healthy individuals. In another study, polymorphism significantly influences postprandial Ghrelin and leptin levels, potentially impacting hunger and satiety in morbidly obese women and overweight men.

Ghrelin and Leptin: AA genotype of FTO rs9939609 would have higher postprandial acylated ghrelin (AG) levels and energy intake.

Protein Intake Interaction: The A allele may be associated with a high decrease in food cravings and appetite scores with a high-protein diet.

Conclusion: The overall findings from these studies underscore the complex role of the FTO rs9939609 variant in regulating appetite and related hormonal responses. The genotype appears to modulate hunger, appetite, and food cravings through various mechanisms, including hormonal changes, exercise responses, and dietary interactions.