If sugar is always your jam, your DNA may be to blame. An international team of researchers says that a genetic variation in our ability to digest certain sugars may influence how much we like sweet foods — and how much we consume. The scientists are pointing the finger at the sucrase-isomaltase (SI) gene, which plays a key role in breaking down sucrose (also known as table sugar) and maltose (a less sweet compound found in some cereals) into simple sugars for absorption by the small intestine.

Mutations in the GI gene can make it difficult to digest sucrose and maltose. People with irritable bowel syndrome tend to have more defective SI gene variants than healthy people. About 10% to 15% of American adults suffer from IBS, which is characterized by cramping, bloating, stomach fullness or burning sensations, often accompanied by diarrhea or constipation.

For the new research, the study authors explored the dietary habits of mice that lacked the SI gene. The vermin rapidly reduced their sucrose consumption and preference for it. The researchers then tested their theory on 6,000 people in Greenland and nearly 135,000 UK residents.

They found that those in Greenland who couldn’t digest sucrose at all consumed significantly fewer sucrose-rich foods, while the UK residents with a partially functional SI gene preferred sucrose-rich foods less. The results were published Tuesday in the journal Gastroenterology . “These findings suggest that genetic variation in our ability to .