Food Intolerance refers to a number of conditions.

Lactose Intolerance

Lactose intolerance occurs when the body does not produce enough of the enzyme lactase to digest the lactose in dairy products. It presents as abdominal pain or discomfort and diarrhoea after consuming dairy products containing lactose. 

In many people lactose intolerance is genetic however there are other causes such as gut damage from gastroenteritis or other gut conditions such as Coeliac Disease.  It is important to ask your GP to do the right investigations if you are not sure why you have lactose intolerance.

I can help you manage your lactose intolerance and give you guidance on whether it is a true lactose intolerance or identify other dietary components are contributing to your symptoms.



FODMAPS stands for Fermentable -Oligo-Di-Mono-sacharides and Polyols, in other words these are the ‘windy foods’.  In anyone a high enough amount of the FODMAPS foods give an array of gut symptoms such as bloating, pain and diarrhoea.  Those with IBS do not have more wind in their bowel from these windy foods but have more nerve endings in  their gut (likely caused by the food chemicals) which means they sense the discomfort more. Understanding the food triggers is important in management.


Food Chemical Intolerance

Food chemical intolerance occurs when symptoms are caused by one or more natural (salicylates, amines, glutamates) or artificial food chemicals common to many different foods.  People who are intolerant usually react to more than one food component and those very sensitive also react to cows milk, soy or wheat. 

Food chemical intolerance can often seem outright weird. It can affect more than one body system and even look like an allergy.  The way various symptoms are affected by food components are as unique as each person’s face.  Some symptoms of food chemical intolerance include but are not limited to:

Skin- eczema, unexplained rashes, hives, itchiness, skin swellings (angioedema).

Gut- mouth ulcers, reflux, irritable bowel syndrome (IBS), abdominal pain, bloating, excess wind, diarrhoea, constipation.

Respiratory- non-allergic rhinitis (hayfever symptoms).

Central nervous system- sleep problems, poor concentration, mood swings, hyperactivity, headaches, migraines, anxiety, depression.


Food chemical intolerance is not well known by all health professionals including general dietitians.  It is a very complex area and requires a professional with the specialist knowledge and expertise to make an assessment, rule out other medical conditions and provide the right advice. 

There are no reliable medical tests that can identify what food components or chemicals a person is intolerant to.  Food chemicals have a build up effect in the body.  Symptoms can be delayed for up to 3 days after eating the trigger and they can last for up to 3 weeks in people who are very sensitive. 

The RPAH Elimination diet with challenges is the only best test method to find out what food chemicals are the problem. After the test diet and challenges are complete the diet variety is increased (liberalisation) and food chemical tolerance levels can be increased slowly and gradually over time.

As a Specialist Food Intolerance Dietitian I strongly encourage my clients to keep in touch with me throughout the elimination, challenging and liberalisation phase of the RPAH Elimination Test Diet to ensure you are complying with the diet, interpreting symptom reactions correctly during the different phases, obtain information on the challenging procedure and receive guidance when liberalising and increasing your tolerance threshold.