Many of us have ditched our favourite sugary drinks for their diet alternative in a bid to boost our health and keep off the pounds.

But it seems that diet drinks can be just as bad for you, according to a study.

Scientists found drinking just two glasses of diet drinks a day more than doubles the risk of developing diabetes.

They believe that calorie-free drinks make us feel hungrier, prompting us to crave sugar-laden snacks.


And they also suspect that artificial sweeteners interfere with the bacteria in our gut - which may trigger diabetes.

The team from the Karolinska Institute in Sweden studied 2,874 adults who had completed a year-long diary about their intake of drinks.

Those who had two or more sweetened drinks a day were 2.4 times more likely to develop type 2 diabetes. This included sugary beverages and artificially sweetened ones, such as Diet Coke or sugar free cordials.

Having five or more sugar-free drinks a day increased the risk by 4.5 times.

In fact, the researchers found that artificially-sweetened drinks were almost as bad as those laden with sugar.

They established that every 200ml glass of a sugary fizzy drink consumed each day increased the risk of type 2 diabetes by 21 per cent.

Meanwhile every diet drink increased the risk by 18 per cent, according to the findings published in the European Journal of Endocrinology.

Lead researcher Josefin Löfvenborg said diet drinks may 'stimulate the appetite', leading to weight gain.


She added that artificial sweeteners may cause chemical reactions within fat tissue and with bacteria in the gut.

This can lead to the body becoming less tolerant of glucose - a form of sugar - triggering type 2 diabetes. She said: 'One hypothesis is that consumption of diet soft drinks may stimulate appetite making us increase our food intake, especially sweet or sugary foods, possibly leading us to become overweight which is a risk factor for diabetes.

'It has also been proposed that artificial sweeteners may negatively affect the balance of "good" and "bad" species of microbes in the gut, leading to glucose intolerance.'

The researchers now want to assess whether eating certain healthy foods, such as oily fish, can help reverse this risk.

Around 3.3million Britons have been diagnosed with diabetes and the majority have type 2 - which is partly caused by obesity.

Figures published by the NHS this summer showed it was spending £1billion a year on drugs to treat the illness.

Last November scientists at the Karolinska Institute also found that men who had two diet drinks a day were 23 per cent more likely to develop heart failure.

And last autumn Professor Graham MacGregor, a consultant cardiologist at Barts and the Royal London Hospital, called on MPs to extend the sugar tax to diet drinks as they 'still lead to obesity.'

Last night Dr Elizabeth Robertson, of Diabetes UK, said adults who consumed diet or sugary drinks tended to be unhealthier generally than those who stuck to water, meaning they had a higher risk of type 2 diabetes anyway, adding that more research on diet drinks was needed.