According to a recent study published in the New England Journal of Medicine, a genetic mutation may contribute to overeating. The study focused on a group of children who carried a variant of rs9939609, a fat mass and obesity-associated (FTO) gene; in their tests, the researchers found that children who carried the variant gene ate more at meal times than controls. According to Colin N.A. Palmer, Ph.D., of the University of Dundee’s Biomedical Research Institute at Ninewells Hospital and Medical School, and colleagues, there are “indications that there is no defect in metabolic adaptation to obesity… In the total study group, the A allele of rs9939609 was associated with significantly increased weight (P =0.003) and BMI (P=0.003).” The following is an excerpt of an article by Medpage Today that discusses the findings more:
On the basis of the skinfold measurements, “children who carried the A allele had an estimated fat mass that was 1.78 kg greater than that of non-carriers (P=0.01) and an estimated lean mass that was less than 400 g greater than that of non-carriers ( P=0.46).
The authors said that their data “suggest that the [fat mass and obesity-associated] gene influences the ‘input’ side of the energy-balance equation,” a finding already reported in animal studies.
Thus the key to preventing obesity in people with this genotype, which occurred in 0.385% of the population studied, would be “moderate and controlled restriction of energy intake.”
In an editorial, Rudolph L. Leibel, M.D., of Columbia University in New York, wrote that the frequency of the rs9939609 A allele has been estimated as “0.45 in Europeans, 0.52 in West Africans, and 0.14 in Chinese.”
And even though the “locus accounts for only a small proportion of differences in BMI in the entire population, it plays a substantial role — in these people, in these environments — in conveying the risk of actually becoming overweight or obese.”