'Fat gene' carriers should forgo fried foods, study finds

People with genes that predispose them to excess weight and obesity are more likely to put on weight from eating fried food, a study says.

Several 'fat genes', genetic markers strongly linked to obesity, have been identified previously (see BioNews 746, 743 and 739 for recent examples) but this research is the first to demonstrate their impact on the adverse effects of fried food.

The study, published in the BMJ, analysed data from three large trials involving more than 37,000 subjects. Genetic risk scores for obesity were generated based on 32 single nucleotide polymorphisms (SNPs) previously shown to influence body mass index (BMI). The large study size was necessary because these SNPs have a relatively subtle effect on BMI.

Participants in the trials completed questionnaires in which they indicated how frequently they consumed fried food. Weight and height measurements were taken repeatedly for between three and 14 years.

Perhaps unsurprisingly, people who ate fried food frequently typically had higher BMI. But the association between overconsumption of fried food and obesity was particularly pronounced among those with a high genetic risk score.

Consuming fried food more than four times a week had twice the effect on BMI for those in the highest third of genetic risk score compared to those in the lowest third.

'This work provides formal proof of interaction between a combined genetic risk score and environment in obesity', said Professor Alexandra Blakemore and Dr Jess Buxton, both of Imperial College in London, UK, in an accompanying editorial.

However, they also added that the results 'are unlikely to influence public health advice, since most of us should be eating fried food more sparingly anyway'.