There has been a huge rise in the number of products sold to people concerned they suffer from food allergies or intolerances.
Some people do not eat dairy products
Research by Mintel shows the market for products "free from" potential problem foods such as dairy, gluten, wheat and nuts grew by 165% between 2000 and 2002.
Last year, the market was valued at £55.6m - the sector is forecast to reach £138m by 2007.
Mintel say the market has grown because more people believe they have a food allergy or intolerance.
Researchers suggest it has become fashionable to have the 'designer disorder' and that it is fashionable to have an intolerance or allergy.
There is a large discrepancy between the public perception of food allergy and intolerance and the incidence
British Nutrition Foundation spokeswoman
Mintel adds that growing awareness amongst the medical profession of the problems has boosted the market, as more people are advised to follow elimination diets to test for food intolerance.
A survey of 1,000 housewives carried out by Mintel, found one in 10 avoided eating wheat, lactose and gluten, compared to nearly two in three who avoid high-fat foods, one in three who avoid sugar and saturated fat, one in four who avoid salt and one in five who avoid artificial additives, spicy foods and shellfish.
But only a small number said their biggest health worry was a food intolerance or allergy.
Just 12% said their biggest worry was irritable bowel syndrome, 4% worried about wheat intolerance, 2% about gluten lactose and gluten intolerances and 3% about nut and other food allergies or intolerances
In contrast, a third were most concerned about high blood pressure and a quarter about high blood cholesterol.
James McCoy, a senior consumer analyst for Mintel, said: "As well as avoiding food for food intolerance and allergies, these foods will also be avoided for other reasons as well.
"For example, cheese and nuts are high in fat, consequently, these responses overplay concerns about allergies.
"This indicates that food intolerance and food allergies are a less common reason than healthy eating for avoiding particular foods and
ingredients, but nevertheless point to a substantial market demand for specialist foods."
He said consumers would increasingly be looking to shops to stock foods to enable them stick to their special diets with the minimum of effort and inconvenience.
A spokeswoman for the British Nutrition Foundation said: "There is a large discrepancy between the public perception of food allergy and intolerance and the incidence of diagnosed food allergy that is reported in the scientific literature.
"Some sources have suggested that as many as 20 to 30% of adults in the UK believe they have a food allergy or intolerance.
"However when the same people have been tested the reality is quite different - official figures fall between 1-2%."
She said food allergies and intolerances were more common in children, though most outgrew them by the age of five.
She added health professionals were concerned that some people were being encouraged, unnecessarily, to eliminate key foods from their diets such as wheat and milk.
"These are foods that provide a wide range of important nutrients and play a key role in most people's diets.
"If alternative sources of nutrients aren't included in the diet, this can lead to long term health problems, such as nutrient deficiencies."