Food Intolerance and Allergies

Why is it necessary?

Food intolerance is an adverse reaction to a specific food or food ingredients that occur each time the same food or food ingredient is eaten. Allergy is one type of food intolerance.

Who would require the diet?

Individuals who have a proven reaction to a food should avoid foods known to cause them problems. Although there are many people that feel they have an allergy, research in carefully controlled trials show that the actual number is very small. Sometimes a psychological based aversion to foods can be the problem this is known as food aversion.

What is the diet and how does it work?

The diet is simple in principle, as it involves avoiding the food or group of foods that are known to cause the intolerance. Well known intolerances are Coeliac disease (see gluten free diets), milk allergy to milk protein or lack of the enzyme (lactase) to digest milk (see milk free diets) and peanut allergy (see peanut free diets).

Will the diet harm me?

The basis of good health is eating a balanced diet. Removing a food may not have any detrimental effect to the diet, however, the more common the food is in the diet the more likely it is to cause a nutritional problem should it be removed. For example, milk is very common and removing it from the diet is likely to cause nutritional problems. Less common intolerances to foodstuffs such as coffee are much easier to manage and do not really present any nutritional problems.

What else do I need to know?

The most reliable way to assess if a food is causing a problem is to omit it from the diet, and then reintroduce it later on to see if the original symptoms reoccur. This however does take time as often the culprit is not initially known and it is a matter of detective work to establish if what the problem is.

The best method is to try an exclusion diet. This is a diet based on a few foods only, which is followed for 3 weeks, and the original symptoms should have disappeared. Possible offending foods are reintroduced into the basic diet at approximately 2-day intervals, and an intolerance is suspected if the introduced food causes problems.

If a food is suspected as causing an 'intolerance', removing it from the diet may solve the problem. If there is no improvement after 4 weeks then the food should be reintroduced to the diet.

A slightly easier method is to continue eating the usual diet but to record what is eaten in a food diary along with symptoms. It may be possible to match up the symptoms with the food and then eliminate it from the diet.

There are numerous tests available which claim to identify potential food allergies. The British Allergy Foundation provides information on some of these tests, including those which are regarded as non-conventional and have no place in allergy testing.

Because of the risk of eating an unbalanced diet for food intolerances, it is important to seek help from professional, qualified individuals who can assess the nutritional adequacy of the diet and help with choosing appropriate foods.

Where else can I seek help?

A State Registered Dietitian can help assess if the diet is nutritionally balanced and provide practical suggestions with the diet. All doctors have access to a dietitian within the NHS alternatively you can contact the British Dietetic Association who can provide names of qualified dietitians who offer their services privately and who are able to help.

The British Dietetic Association
5th Floor,
Charles House
148/9 Great Charles Street Queensway
Birmingham B3 3HT

Tel: 0121 200 8080
Fax: 0121 200 8081

British Allergy