Swapping fizzy drinks for water could significantly decrease the risk of diabetes and heart disease, say scientists.

Leading researchers from Harvard University are presenting new evidence which shows replacing sugar-sweetened drinks with water can lead to weight loss and help reduce the risk of Type 2 diabetes by seven per cent.

They will present groundbreaking findings and applications on the importance of healthy hydration at the Sustaining the Blue Planet: Global Water Education Conference.

Professor Frank Hu, from the Harvard School of Public Health, said: "There is convincing evidence that regular consumption of sugar-sweetened beverages is associated with increased risk of obesity and diabetes, and emerging evidence that these beverages increase the risk for heart disease.

"To reduce risk of obesity and cardiometabolic diseases, it is important to reduce consumption of sugar-sweetened beverages and replace them with healthier choices such as water and unsweetened tea or coffee."

The International Chair on Cardiometabolic Risk (ICCR), which conducted the research, says more than 100,000 people are diagnosed with Type 2 diabetes every year, with 26 million Brits projected to be obese by 2030.

ICCR scientific director, Dr Jean-Pierre Depsres said: "The epidemic prevalence achieved by abdominal obesity can be explained by our sedentary lifestyle and poor nutritional habits, among which an overconsumption of sugar-sweetened beverages plays a significant role. Until recently, these beverages have escaped the scrutiny that low-quality foods have received, but as our research shows, this certainly should not be the case."

According to NHS figures, more than 2.8 million people in the UK have diabetes.