A single gene could be the reason why some of us carry an extra 30 pounds of fat

By the time they reach adulthood, they could be up to 30 pounds (13.6 kg) heavier with the excess weight likely to be mostly fat.

The NIHR Cambridge BRC-supported study found that when the MC4R gene does not work properly, our brains think we have lower fat stores than we do, signalling that we are starving and need to eat.

These results were found by studying the MC4R gene in a random sample of around 6,000 participants born in Bristol in 1990-91, who were recruited to Children of the 90s, a health study based at the University of Bristol.

Based on the frequency of mutations in this study, it is possible that around 200,000 people in the UK could carry a substantial amount of additional fat because of mutations in MC4R.

In the longer term, knowledge of the brain pathways controlled by MC4R should help in the design of drugs that bypass the signalling blockade and help restore people to a healthy weight.

This is an abridged version of the article first published on our website on 28 May 2021.