FTO rs9939609 genotype and behavioral determinants of Mediterranean diet adherence in young women: exploratory insights into potential metabolic relevance

Abstract

Introduction Metabolic disorders such as obesity and insulin resistance result from complex interactions between genetic, behavioral, and dietary factors. The fat mass and obesity-associated (FTO) gene has been repeatedly linked to impaired appetite control and higher obesity risk, yet the moderating role of functional dietary patterns such as the Mediterranean diet remain unclear. Rich in bioactive compounds and metabolic benefits, this diet offers a model for studying gene–diet interactions in metabolic health. Objectives This pilot investigation aimed to provide an integrative perspective linking the FTO rs9939609 genotype with eating-related emotions, habitual behavior, and adherence to a Mediterranean-style diet in women with different body weight profiles. Methods This pilot study examined associations between the FTO rs9939609 genotype, eating behaviors, and adherence to the Mediterranean diet among 46 women aged 18–35 years (normal weight: n = 24; overweight or obesity: n = 22). Eating behaviors were assessed with the Questionnaire of Eating-Related Behaviors (QERB), and diet quality was evaluated using the Mediterranean Pyramid (MedPyr) index. Genotyping was performed by Sanger sequencing. Results Women with overweight or obesity showed higher BMI (p < 0.001) and greater habitual overeating (p = 0.007), particularly among FTO AT/AA carriers with overweight or obesity. Total QERB scores were higher in both TT (p = 0.037) and AT/AA (p = 0.005) subgroups. No significant genotype- or BMI-related differences were observed in overall MedPyr adherence. However, AT/AA carriers with overweight or obesity reported more frequent vegetable intake (p = 0.037), while AT/AA controls consumed eggs more often (p = 0.015). Conclusion Adherence to the Mediterranean diet, a functional dietary pattern rich in polyphenols, fiber, and unsaturated fats, may interact with genetic predispositions related to obesity risk. These exploratory findings suggest that dietary context may shape behavioral tendencies in FTO risk-allele carriers, although confirmation in larger samples is required.