London, Mar 15 (IANS): Drinking coffee, a rich source of caffeine, may help curb the amount of body fat and reduce the risk of developing Type 2 diabetes, suggests a study.

Researchers from the Imperial College London found that people who carry genetic variants associated with slower caffeine metabolism drink, on average, less coffee, yet have higher levels of caffeine in their blood than people who metabolise it quickly to reach or retain the levels required for its stimulant effects.

The research published in the journal BMJ Medicine concluded that the speed at which coffee is metabolised by the body may impact the weight.

To find out, the study looked at the role of two common genetic variants of the CYP1A2 and AHR genes in nearly 10,000 people of predominantly European ancestry.

The CYP1A2 and AHR genes are associated with the speed of caffeine metabolism in the body.

The results of the analysis showed that people with higher plasma caffeine levels enjoyed a lower body mass index (BMI) and body fat, alongside a lower risk of developing type two diabetes.

"Ninety-five per cent of your caffeine is metabolised by an enzyme," Dipender Gill, clinical scientist at the Imperial, was quoted as saying Independent.co.uk.

"Two genes - CYP1A2 and AHR - affect the function and level of that enzyme.

Using these genetic variants, the team found that slower metabolisers have higher plasma (blood) caffeine levels, and those with higher plasma levels go on to have a lower BMI and risk of diabetes, Gill said.

"It's the plasma caffeine that's doing that," he noted.

However, more research is needed, the team said. It is because caffeine has been associated with lower sleep quality and increased palpitations.