Good fat, bad fat

It may seem counter-intuitive, but researchers have identified that a gene associated with lower percentages of body fat is also linked with an increased risk of type 2 diabetes and heart disease.

Researchers at the Harvard Medical School affiliate, the Institute for Aging Research, Hebrew SeniorLife, examined the genomes of more than 75,000 people to look for the genes that determine body fat percentage.

A gene called IRS1 was linked with less body fat – as well as unhealthy levels of cholesterol and blood glucose. The scientists found that the IRS1 gene lowers only the subcutaneous fat under the skin, but not the more harmful visceral fat that surrounds organs. 

The study authors hypothesised that people with this gene variant are less able to store fat safely under the skin and may instead store fat elsewhere in the body.

The effect seemed to be more pronounced in men than women, possibly due to the different body fat