EXTREME diets from internet sites could be risking the lives of people who choose to follow them.

Warrington Trading standards is supporting a campaign to raise awareness about Very Low Calorie Diets (VLCD) by the National Obesity Forum.

These diets ban all normal food and replace meals with shakes, soups, mousses or bars, which contain all of the nutrients needed for the day and provide around 500 calories.

Once all the excess weight has been lost, people then return slowly to conventional food.

These diets are only recommended for people who have a body mass index (BMI) of 29 or above, which means people who are verging on obesity.

However, the National Obesity Forum suggests that a VLCD should only be used when cleared of any major illnesses under close medical and dietetic supervision.

Serious side effects of VLCDs include development of gout, gallstones and cardiac disturbances.

Doctor David Haslam from the National Obesity Forum, said: "Someone who thinks that maybe they need to lose a couple of pounds here and there to get into a bikini for the summer holidays might think a VLCD is a great idea when it isn't.""

He added: "If someone who's not overweight or obese does get into the habit of losing weight then it could potentially lead to eating disorders or the worsening of eating disorders."

Trading standards is advising everyone to seek medical advice from your GP before going on any extreme diets.