Assessment of the FTO gene polymorphisms (rs1421085, rs17817449 and rs9939609) in exercise-trained men and women: the effects of a 4-week hypocaloric diet

Abstract

Background Variations in the fat mass and obesity-associated gene (FTO) are associated with obesity; however, it is unclear if changes in energy intake affect the adaptive response to caloric restriction in those with risk variants. The three FTO single nucleotide polymorphisms (SNPs), rs1421085, rs17817449 and rs9939609, are in strong linkage disequilibrium. Thus, the purpose of this investigation was to determine the role of these FTO SNPs vis-à-vis the effects of a 4-week hypocaloric diet on body composition in exercise-trained men and women. Two salivary biomarkers that associate with energy expenditure were also assessed (cortisol and salivary alpha-amylase, sAA). Methods Forty-seven exercise-trained men ( n = 11) and women ( n = 36) (mean ± SD: age 32 ± 9 years; height 169 ± 8 cm, body mass index 24.5 ± 2.9 kg/m 2 , hours of aerobic training per week 4.9 ± 3.8, hours of weight training per week 3.9 ± 2.4, years of training experience 13.4 ± 7.0) completed a 4-week hypocaloric diet (i.e., decrease total calories by ~ 20–25% while maintaining a protein intake of ~ 2.0 g/kg/d). Subjects were instructed to maintain the same training regimen and to decrease energy intake via carbohydrate and/or fat restriction during the treatment period. Body composition was assessed via dual-energy X-ray absorptiometry (DXA) (Model: Hologic Horizon W; Hologic Inc., Danbury CT USA). Total body water was determined via a multifrequency bioelectrical impedance (BIA) device (InBody 770). Saliva samples were collected pre and post intervention in order to genotype the participants as well as to determine the concentrations of cortisol and sAA. Results Of the 47 subjects, 15 were of normal risk for obesity whereas 32 were carriers of the FTO gene risk alleles. Subjects were grouped based on their genotype for the three FTO SNPs (i.e., rs1421085, rs17817449 and rs9939609) due to their strong linkage disequilibrium. We have classified those with the normal obesity risk as “non-risk allele” versus those that carry the “risk allele” (i.e., both heterozygous and homozygous). Both groups experienced a significant decrease in total energy intake ( p < 0.01); non-risk allele: pre kcal 2081 ± 618, post kcal 1703 ± 495; risk allele: pre kcal 1886 ± 515, post kcal 1502 ± 366). Both groups lost a significant amount of body weight ( p < 0.01); however, there was no difference between groups for the change (post minus pre) in each group (risk allele change: − 1.0 ± 1.2 kg, non-risk allele change: − 1.2 ± 1.4 kg). Additionally, both groups lost a significant amount of fat mass ( p < 0.01) with no differences between groups for the change in fat mass (risk allele change for fat mass: 1.1 ± 0.7 kg, non-risk allele change − 0.9 ± 0.4 kg). There were no significant changes in either group for fat free mass or total b...

Comparison of visceral fat area measured by CT and bioelectrical impedance analysis in Chinese patients with gastric cancer: a cross-sectional study

“…Further studies to validate the conclusions using the promotion product InBody 770 should be performed. 38 In conclusion, it is necessary to identify visceral obesity in patients with gastric cancer both prior to surgery and in the aftercare period via body composition analysis. The present study revealed that the VFA measured by CT and BIA showed significant correlation and satisfactory reliability.…”

“…Further studies to validate the conclusions using the promotion product InBody 770 should be performed. 38 …”

An intron variant of the GLI family zinc finger 3 (GLI3) gene differentiates resistance training‐induced muscle fiber hypertrophy in younger men

“…12 Using these search criteria we identified 183 records dating from 1994-2019, and of these, 158 records were removed for not meeting the inclusion criteria. Additional search tools (ie, searching relevant search terms through Google Scholar and hand-searching reference lists of identified papers) were used to add 5 additional records, 8,[13][14][15][16] and this resulted in a total of 30 scientific studies containing relevant criteria. [6][7][8] From these studies, 20 gene candidates were identified, and of these, the 10 polymorphisms present on the array were interrogated in the current study (Table 1).…”

The association between FTO genotype with macronutrients and calorie intake in overweight adults

“…FTO gene has an important role in regulation of food intake, energy balance, appetite, and basal metabolic rate (BMR) [ 11 , 12 ]. Polymorphisms in the intron regions of FTO gene may act as a regulator of other genes such as Iroquois homeobox 3 ( IRX3 ) and obesity-associated single nucleotide polymorphisms of FTO were associated with expression of IRX3 , but not FTO , in human brains [ 11 ].…”

“…Polymorphisms in the intron regions of FTO gene may act as a regulator of other genes such as Iroquois homeobox 3 ( IRX3 ) and obesity-associated single nucleotide polymorphisms of FTO were associated with expression of IRX3 , but not FTO , in human brains [ 11 ]. On the other hand, FTO genotypes may influence the association of dietary macronutrients with Body Mass Index (BMI), body weight, food intake, energy balance, appetite, and hormone secretion [ 12 – 14 ]. Dietary macronutrients including carbohydrate, fat, and protein, as the main sources of energy, play key roles in regulation of body weight and BMI [ 14 , 15 ].…”