Impact of FTO Gene Variation on Body Composition, Lipid Profile, Insulin Resistance, Advanced Glycation End-Products and Ghrelin Levels in Response to Hypocaloric, Protein Rich-Diet

Obesity is a widespread disease that basically develops from unhealthy lifestyle and genetics. The Fat-mass and obesity associated (FTO) gene affects appetite and energy intake of the body, thus elevating fat mass and body weight. The single nucleotide polymorphism (SNP) rs9939609 of the FTO gene is a common variant in different ethnic groups, and its A allele is associated with increased body mass and waist circumference. Hence, the carriers of rs9939609 SNP are prone to weight gain if a healthy diet and lifestyle are not maintained. Similarly, high levels of serum cholesterol and triglycerides, while low levels of high-density lipoproteins are observed in carriers of rs9939609 AA genotype. For individuals having FTO rs9939609 A allele, consumption of hypocaloric diets (1500 kcal/day) consisting of high protein foods up to 25-30% of total daily energy intake might help reduce body weight. However, weight loss tends to vary in individuals after consuming the same diet under similar environmental conditions, so it is important to know the effect of different genotypes that might cause this variation. The study aimed to genotype overweight and obese adults for FTO rs9939609 polymorphism and to determine the effect of this polymorphism on body weight, BMI, waist and hip circumferences, lipid profile, insulin sensitivity, ghrelin levels, inflammatory markers and advanced glycation end-products in these individuals after consumption of a hypocaloric, high-protein diet for 4 weeks.