These findings hold promise for the future development of calorie-free caffeinated beverages to tackle obesity and type 2 diabetes.

Elevated levels of caffeine in the bloodstream could potentially lead to a decrease in body fat and a reduced risk of developing type 2 diabetes, a new study published in the BMJ Medicine journal found.

This revelation may pave the way for calorie-free caffeinated beverages to be employed in combating obesity and type 2 diabetes. However, the researchers emphasise that additional investigations are necessary to fully understand these implications.

The study’s findings built on previously published research suggesting a link between daily consumption of three to five cups of coffee, containing 70-150mg of caffeine on average, and a lower risk of type 2 diabetes and cardiovascular disease.

These earlier studies were observational, making it difficult to determine whether the observed effects could be attributed to caffeine or other compounds found in coffee.

To establish causation, the research team employed a technique known as Mendelian randomisation, which utilises genetic evidence to determine cause and effect. The researchers identified two common gene variants related to the rate in which caffeine is metabolised.

By examining these gene variants, the team was able to estimate genetically predicted blood caffeine levels and analyse their association with lower body mass index (BMI) and body fat.

Interestingly, individuals who possess genetic variants linked to slower caffeine metabolism tend to consume less coffee on average, yet exhibit higher levels of caffeine in their blood compared to those who metabolise caffeine rapidly.

The study found that nearly 50% of the reduction in type 2 diabetes risk could be attributed to weight loss.

Caffeine is known to increase metabolism, enhance fat burning and suppress the appetite.

A daily caffeine intake of 100mg is estimated to raise energy expenditure by approximately 100 calories per day.

Despite these promising findings, there are limitations to the study. The research was based on data from nearly 10,000 participants, primarily of European descent, who were involved in six long-term investigations.

Further research is needed to determine if these findings apply to a more diverse population.