Background/aims: The common polymorphism in the FTO gene (rs9939609) has been associated with obesity, type 2 diabetes, and appetite regulation. The aim of this study was to evaluate possible associations of FTO rs9939609 with dietary factors in patients with type 2 diabetes.

Methods: This was a cross-sectional study of 236 patients with type 2 diabetes (age 60.0 ± 10.3 years; diabetes duration 12.7 ± 8.2 years; 53.4% females) who were genotyped for FTO rs9939609. Patients underwent clinical and laboratory evaluations and 3-day weighed diet records. Data on dietary intake were categorized as high or low, based on median values.

Results: The AA genotype in the FTO gene was positively associated with high fat (>34% energy; OR = 2.17; 95% CI 1.02-4.63) and low fiber intakes (<16 g/day; OR = 2.42; 95% CI 1.05-5.57), adjusted for gender, BMI, total energy intake, systolic blood pressure, and HbA1c. When gender was taken into account, AA females had higher fat (37.4 ± 5.3 vs. 32.6 ± 7.5 and 32.2 ± 6.2% energy; p = 0.005) and lower fiber intakes (12.4 ± 4.4 vs. 15.1 ± 6.3 and 16.7 ± 5.6 g/day; p = 0.023) than patients with TT and AT genotypes. Multiple logistic regression models confirmed female associations for high fat (OR = 9.73; 95% CI 2.12-44.66) and low fiber intakes (OR = 4.28; 95% CI 1.14-16.06; p < 0.05 for all models).

Conclusions: Patients with type 2 diabetes, who were carriers of the AA genotype of the FTO rs9939609, had increased fat and decreased fiber consumption, independently of BMI.