If you are restricting your diet because of an allergy or intolerance you need to be sure that you only cut out the real ‘problem’ foods to avoid nutrient deficiencies. True food allergy is quite rare (1% of the population) and usually involves a sudden and severe antibody reaction.
Nuts, cow’s milk, eggs and fish are common allergens and a reaction may involve swelling, skin rash, breathing difficulties, or in the worst cases anaphylaxis. If you think you may have a food allergy ask your GP to refer you to a specialist or to do IgE blood tests for specific foods. With allergies a proper medical diagnosis is essential so be very cautious of unconventional tests or dubious practitioners.
Food intolerances may present in many different ways including digestive disorders, chronic fatigue or migraines and tend to occur hours after consuming the problem food. Whilst these adverse reactions are rarely life threatening they can nevertheless be extremely debilitating and are very common (up to 20% of the population). Unfortunately there is no scientific evidence to support any of the commercial tests for food intolerance (don’t be conned!) so diagnosis involves eliminating suspect foods from the diet and seeing if the symptoms resolve by a process of trial and error.
The risk with food intolerances is that important food groups might be unnecessarily restricted from the diet and result in deficiencies. If you have initial improvements on a ‘free from’ diet be sure to try reintroducing the food to test your theory and whilst you are trying to work out what the problem is only restrict one food type at a time.