No relationship between so-called “obesity gene” and ability to lose weight

By Bruce Sylvester

There is no relationship between the so-called ‘obesity gene’ (FTO genotype/rs9939609) and the ability to lose weight, researchers reported on Sept. 21, 2016 in the BMJ/British Medical Journal.

Weight loss strategies, “should focus on improving lifestyle behaviours, principally eating patterns and physical activity, since these will be effective in achieving sustained weight loss irrespective of FTO genotype,” the authors concluded.

As background, the authors noted that some experts believe that genes play a significant role in the development of obesity, and others believe that environmental changes are responsible for increasing obesity rates.

The investigators included in the new meta-analysis 8 randomized controlled trials enrolling 9,563 overweight or obese adults, and in which researchers evaluated reduction in body mass index, body weight, or waist circumference by FTO genotype after dietary, physical activity, or drug based interventions.

In the meta-analysis, they found that, “Overall, differential changes in body mass index, body weight, and waist circumference in response to weight loss intervention were not significantly different between FTO genotypes. Sensitivity analyses indicated that differential changes in body mass index, body weight, and waist circumference by FTO genotype did not differ by intervention type, intervention length, ethnicity, sample size, sex, and baseline body mass index and age category.”

In a linked editorial, Dr Alison Tedstone, chief nutritionist at Public Health England, said that the causes of the obesity epidemic are complex, but current evidence does not support an emphasis on gene profiles. She said that, “a rebalancing of research towards whole systems approaches including environmental drivers may be of greater benefit to the population in the long term.”