Scientists may have found out why some people appear to be able to eat whatever they want without gaining weight. According to a new study, individuals with a particular variation of the FGF21 gene tend to crave sugary foods, but are also more likely to have less body fat than others.
The FGF21 gene is responsible for a hormone that regulates metabolism and the storage of glucose sugars as fat. The gene can suppress or trigger cravings and “appears to make tissues more sensitive to the effects of insulin,” which has caught the attention of drug developers, according to Cosmos.
Around 20% of Europeans have what is known as the A variant of FGF21. Since 2013, scientists have known that carriers of this variant tend to consume more carbohydrates than others.
Led by the University of Exeter, the new study was conducted by an international team of researchers and published in journal Cell Reports on Tuesday.
In order to learn more about the effects this genetic variation might have on human metabolism and diet, researchers analysed health information data recorded in the UK Biobank from over 450,000 individuals. The information included genetic data, blood samples, diet questionnaires and other health and lifestyle data.
Like previous studies, the team found that individuals who carry the A variant of FGF21 were more likely to crave a high-carb diet. The analysis showed a link between the A variant and increased sugar intake and found “unequivocal statistical evidence” that it was associated with higher alcohol intake.
Interestingly, researchers also found that individuals carrying the A version of the gene were not typically overweight and tended to have less body fat than others.
“We were surprised that the version of the gene associated with eating more sugar is associated with lower body fat,” said Professor Timothy Frayling, leader of the study and a molecular geneticist at the University of Exeter. “This goes against the current perception that eating sugar is bad for health.”
However, the study also found that the A variant of FGF21 was associated with a tendency towards slightly higher blood pressure and an “apple shape,” with more fat carried around the waist where it could impact the organs.
Because of the large number of people involved in the study, the team is “very confident that the results are accurate,” said study co-author Niels Grarup of the Novo Nordisk Foundation’s Centre for Basic Metabolic Research.
Grarup added that the study’s findings could aid the development of new drugs and advance future research into metabolic disorders and related diseases.
“Due to its connection with sugar, FGF21 constitutes a potential target in the treatment of for example obesity and diabetes,” he said. “This research helps us to understand the underlying mechanisms of the hormone and to predict its effects and side effects.”