New research has found that one in every 340 people might carry a mutation in a single gene that makes them more likely to have a greater weight from early childhood and, by 18 years of age, they could be up to 30 pounds heavier with the excess weight likely to be mostly fat.
Many of us could carry up to 17kg of fat due to a change in a single gene
The study led by scientists at the MRC Metabolic Diseases Unit which is part of the Wellcome-MRC Institute of Metabolic Science at the University of Cambridge and the MRC Integrative Epidemiology Unit at the University of Bristol is published in Nature Medicine.
It has been known for a long time that obesity tends to run in families, but it was not until about 20 years ago that scientists started to discover that changes in specific genes can have very large effects on our weight even from early childhood.
One of these genes, the Melanocortin 4 Receptor (MC4R), makes a protein that is produced in the brain where it sends signals to our appetite centres, telling them how much fat we have stored. 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.
The research team found that around one in every 340 people may carry a disruptive mutation at MC4R. People who carry these mutations were more likely to have a greater weight from early childhood and, by 18 years of age, they were on average 17 kg (37 lbs or 2.5 stone) heavier, with the majority of this excess weight likely to be fat.
Image: Weighing scales and tape measure
Reproduced courtesy of the University of Cambridge
The University of Cambridge is acknowledged as one of the world's leading higher education and research institutions. The University was instrumental in the formation of the Cambridge Network and its Vice- Chancellor, Professor Stephen Toope, is also the President of the Cambridge Network.