Celebrity diets are prompting a growing number of people to cut out key foods because of fears of food intolerances and allergies, a GPs' survey suggests.
Actress Rachel Weisz has a wheat intolerance
The study, involving 250 GPs, suggested many people were self-diagnosing such problems because of celebrity food fads like wheat or gluten-free diets.
Two thirds said more patients reported food intolerances in the last year, the poll for Norwich Union Healthcare said.
But 73% of GPs believed their patients reactions were all in the mind.
A separate ICM telephone poll of 1,000 adults found a fifth of people had first found out about food intolerances and allergies from celebrity interviews, magazines and TV shows.
A similar proportion had heard of these problems through friends and family.
Some 94% of GPs believed people did not know the difference between a food allergy and an intolerance.
A food intolerance is defined as an adverse reaction to food such as a like a headache or bloating, while an allergy leads to a response in the immune system.
Some of the most frequently reported conditions were wheat intolerances as suffered by actress Rachel Weisz and former Spice Girl Geri Halliwell.
And dairy intolerances as suffered by actor Orlando Bloom and singer Victoria Beckham.
Practising nutritionist and state-registered dietician Jill Scott said while food allergies and intolerances could be serious for those affected, people should not jump to conclusions based on what they read.
"Excluding particular food groups can upset a balanced and healthy diet.
"Avoiding dairy products, for example, may result in low calcium intake, which can in the long run affect bone health.
"We strongly recommend that anyone with good reason to believe they may be suffering an intolerance or food allergy seeks out professional advice," she said.
However, many doctors are sceptical that food intolerances exist and will not test for them.
Roger Taylor, research director from Dr Foster the independent provider of health care information which carried out the research for Norwich Union Healthcare, said information in magazines can often be misleading.
"People should think first about whether they have a properly balanced diet and if they are concerned about allergies or food intolerances seek the advice of a dietician or their GP," he added.
Professor Peter Whorwell, a consultant gastroenterologist, said food intolerance was quite common in patients with Irritable Bowel Syndrome but there is often a problem identifying which foods might be involved.
"There is research evidence to suggest that testing for IgG food antibodies might help to guide patients towards which foods are most likely
to be causing problems.
"Random exclusion of foods is not a good idea whatever problem a person might be suffering from therefore if an individual can base the process of exclusion on a specific test this would be much more preferable."