The FTO genotype as a useful predictor of body weight maintenance: initial data from a 5-year follow-up study

We examined associations between the fat-mass and obesity-associated (FTO) gene (rs9939609) and any weight change over a 5-year period following a 14-week lifestyle intervention among middle-aged Japanese women.

One hundred twenty-eight Japanese women (BMI >25 kg/m²) participated in a 14-week weight loss intervention between 2004 and 2006. Of the participants, 62 consented to the 5-year follow-up measurement session. Of these women, 47 women who achieved a weight loss of at least 10% from their baseline values during the 14-week intervention were included in the analysis. Body weight, body fat, abdominal fat assessed by CT scans, and metabolic risk factors (i.e., blood pressure, lipids, and glucose) were measured at baseline, post-intervention, and at the 5-year follow-up.

During the 5-year non-intervention period, increases in body weight, fat mass, total abdominal fat, and subcutaneous abdominal fat were significantly greater in subjects with the homozygous minor allele (AA genotype, n=4; 8.5%) than in those with the homozygous major allele (TT genotype, n=31; 66.0%) or heterozygous allele (TA genotype, n=12; 25.5%). In multiple regression analyses, the variation in rs9939609 was a significant and independent predictor (P<0.001) for regaining weight during the 5-year follow-up.

Our data suggest that Japanese women with the risk allele (AA) of rs9939609 may have more difficulty preventing fat gain from reoccurring after weight loss intervention than women with the other genotypes.