New research has shown that individuals with a specific genetic variant were at increased risk of weight gain following consumption of fried food.
Obesity is a major (and growing) public health problem around the world.
It is known that genetics can influence body mass index (BMI); some genetic variants appear to affect the risk that an individual will be overweight or obese. With the exception of very rare mutations that massively disrupt normal energy intake and metabolism - effectively genetic disorders that result in severe obesity from early childhood - obesity is a complex condition with multiple contributory genetic and environmental factors.
Although preventing and treating obesity relies on the modification of individual behaviours (diet and exercise), and at the population level on promoting healthier environments, understanding the genetic contribution to obesity may eventually be helpful in developing or tailoring different approaches to weight maintenance or loss.
In the new study, researchers from the Harvard School of Public Health rated study participants for the genetic risk of obesity based on 32 genetic variants previously linked with BMI. They compared these ‘obesity genetic risk’ scores with recorded consumption of fried foods (which are very high in fat) and BMI. They found that the impact of eating large amounts of fried food (more than four times a week) was twice as high for individuals with high obesity genetic risk scores as for those with low obesity genetic risk scores.
They concluded that genetic variants can modify the impact of an environmental risk factor for obesity, effectively exacerbating the negative impact of an unhealthy diet for individuals with higher genetic risk scores. Commenting on the findings, Professor Alex Blakemore of Imperial College London said that doctors should be aware that some obese patients may be less responsive to lifestyle modifications.
Comment: A recent PHG Foundation report (The Genomics of Obesity) concluded that there is currently insufficient evidence to support clinical genetic testing in relation to obesity except where there is suspicion of a potential genetic obesity syndrome. However, the researchers behind this recent study could forsee some potential utility for genetic testing in identifying those at higher genetic risk, making them aware that they needed to make extra efforts to avoid weight gain, or to achieve weight loss.