By Robert Preidt
"This goes against the current perception that eating sugar is bad for health," said study first author Timothy Frayling.
The gene may reduce body fat because the same "A" version of the FGF21 gene also results in lower protein and fat consumption.
But the discovery does comes with a downside.
"Whilst this version of the gene lowers body fat," Frayling said, "it also redistributes fat to the upper body, where it's more likely to cause harm, including higher blood pressure."
Frayling is a molecular geneticist at University of Exeter Medical School, in England.
Researchers analyzed data from 450,000 people in the U.K. Biobank -- which includes biological samples from hundreds of thousands of people -- to examine links between different versions of the FGF21 gene, diet, body fat and blood pressure.
The analysis found that the "A" version of the gene was associated with higher sugar and alcohol consumption, a lower percentage of total body fat, higher blood pressure and a higher waist-to-hip ratio.
The findings were published April 10 in the journal Cell Reports.
"Because this study has so many people in it, it gave us enough individuals to be confident in the associations we were seeing," study co-author Niels Grarup said in a journal news release. Grarup is an associate professor of metabolic genetics at the University of Copenhagen, Denmark.
The "A" version of the FGF21 gene is common: about 20 percent of people in Europe have the maximum two copies of it, the researchers said.
Studying different variants of FGF21 could help uncover some of the genetic and biological causes of obesity, according to the researchers.