Nutritional Quality's Key Role in the Odds of Overweight in Adults with rs9939609 Polymorphism of FTO Gene- the Role of Manganese and Vitamin D

Background: Obesity and overweight are the most prevailing problem in most countries. Overweight people are very susceptible to diseases such as diabetes, hypertension, cardiovascular disease, metabolic syndrome, and cancers. Adequate intake of micronutrients along with a quality diet that is varied and balanced plays an important role regarding health and the immune system. Numerous studies have investigated the relationship between the quality of diet and different diseases. Genetics is a risk factor of great importance regarding obesity and overweight. Yet, the role of nutrition in relationship with the underlying mechanisms remains unclear and no specific pathways have been identified for this relation.

Methods: A valid food frequency questionnaire was employed to assess dietary intake. We calculated the INQ (Index of Nutritional Quality) of each dietary item using the following formulae: INQ=consumed amount of a nutrient per 1,000 kcal/recommended dietary allowance or adequate intake of that nutrient per 1,000 kcal. In a retrospective chart review, we determined the genotypes of FTO rs9939609 polymorphism (TT/AT/AA) via amplification refractory mutation system-polymerase chain reaction (ARMS-PCR).

Results: Models obtained from the resulting INQs of manganese as a continuous variable in relationship with waist circumference represented a significant association after multivariate adjustment of age, sex, height, fat free mass, weight, body mass index, marital status, TF, fasting blood sugar, low-density lipoproteins, high-density lipoproteins, total cholesterol, insulin resistance, and total energy intake (odds ratio = 0.24, CI = 0.07-0.79).

Conclusions: Intake of vitamin D from sunlight and its nutritional sources and adequate intake of Mn from a wide range of vegetables, legumes, seeds, and grains might be solutions for some overweight cases with FTO rs9939609 polymorphism.

Keywords: Diet Quality; FTO Gene; Index of nutritional quality (INQ); Manganese; Obesity; Overweight; Vitamin D; rs9939609 polymorphism of FTO gene.