Gluten-free diets could be damaging to the health of people who do not have coeliac disease, raising the risk of obesity, diabetes and malnutrition, an expert has warned.
The diet, which excludes all food containing grains like wheat, barley and rye, such as bread and pasta, have been popularised by celebrities like Gwyneth Paltrow who claims cutting out gluten boosts health and aids weight loss.
Wimbledon champion Novak Djokovic, said it helped propel him to World No 1. while Victoria Beckham claims it is how she keeps her trim figure.
But writing in the Journal of Pediatrics, Dr Norelle Reilly, of Columbia University Medical Centre, in New York, warned that gluten-free alternatives were often loaded with fat and sugar and lacked nutrients.
"There is no evidence that processed gluten free foods are healthier nor have there been proven health or nutritional benefits of a gluten free diet. There are no data to support the theory of intrinsically toxic properties of gluten in otherwise healthy adults and children.
"Gluten free packaged foods frequently contain a greater density of fat and sugar than their gluten-containing counterparts.
"Obesity, overweight and new-onset insulin resistance and metabolic syndrome have been identified after initiation of a gluten-free diet.
"It also may lead to deficiencies in B vitamins, folate, and iron, given a lack of nutrient fortification of many gluten-free products."
Just 125,000 people in Britain have coeliac disease, in which gluten brings diarrhoea, bloating, abdominal pain, fatigue and weight loss. But last year a YouGov poll revealed that 60 per cent of adults have bought a gluten-free product and one household in ten - 2.7 million - contains someone who believes gluten is bad for them.
Dr Reilly said the growth in the gluten-free food market was far greater than the actual need and warned that it could lead to people spending more money that was necessary to eat.
"The gluten free diet should be recommended judiciously and patients self-prescribing a gluten free diet should be counselled as to the possible financial, social and nutritional consequences of unnecessary implementation," added Dr Reilly.
Naveed Sattar, Professor of metabolic medicine at the University of Glasgow said: "This is a well though out point of view and I agree with the points made - people should not adopt a gluten-free diet on the basis that they think it will be beneficial to their health unless they have a diagnosis of a condition such as coeliac disease."
Coeliac disease: FAQ
• Coeliac disease is an autoimmune disease caused by intolerance to gluten, it is not a food allergy.
• Coeliac is pronounced see-liac.
• Gluten is a protein found in wheat, rye and barley. Some people with coeliac disease are also sensitive to oats.
• Damage to the gut lining occurs on eating gluten.
• There is no cure for the condition; the only treatment is lifelong adherence to a strict gluten-free diet.
• People medically diagnosed with coeliac disease and DH can access some gluten-free staple foods on prescription