Food Allergy and Intolerance Testing

As a Clinical Nutritionist, I often ask clients to do a food allergy and/or intolerance test. I have a few different tests available depending on the client’s symptoms.

Food allergies are IgE antibody mediated reactions to proteins in our food. The IgE antibodies are released in response to the food being ingested and pinpointed by our immune system as an allergen. This response results in the release of T2 helper cells which triggers the release of mast cells and basophils. These cells trigger the release of histamine and histamine is responsible for the immediate symptoms of skin rashes, runny eyes and nose, swelling of body parts, heart palpitations etc. As there is an immediate response, the problem food may be easier to identify although allergy symptoms can range from very intense (the body goes into anaphylactic shock) to very mild (bit of runny nose and low-grade itch).

The most common food allergies include:

  • Dairy products – milk, cheese, cream, ice cream etc.
  • Eggs
  • Peanuts
  • Tree nuts (walnuts, almonds, pine nuts, brazil nuts, pecan etc)
  • Soy
  • Wheat
  • Fish
  • Shellfish

On the other hand, food intolerances are driven by an IgG antibody mediated response. There is no immediate histamine release and allergic reaction, and food intolerance symptoms can include but are not limited to:

  • Abdominal pain
  • Anxiety
  • Bloating
  • Breathing difficulties
  • Constipation and/or diarrhoea
  • Depression
  • Dizziness
  • Eczema
  • Fatigue & lethargy
  • Fluid retention
  • Headache
  • Gastric reflux and hyperacidity
  • Hypersensitivity
  • Migraine
  • Nausea
  • Rashes
  • Acne
  • Arthritis
  • Asthma
  • Autism
  • Chronic Fatigue Syndrome
  • Crohn’s Disease
  • Eczema
  • Fibromyalgia
  • Irritable Bowel Syndrome
  • Psoriasis

These symptoms can occur shortly after the food is ingested or up to 2 days later so identifying food intolerances can be a challenge without testing.

The most common food intolerances are:

  • Dairy
  • Eggs
  • Peanuts
  • Soy
  • Gluten or wheat

However, I have found in clinical practice that some clients can have quite random food intolerances like lettuce, walnuts or kiwi fruit.

The scientific consensus behind IgE mediated allergies is quite definitive, the mechanisms of action are well understood and they are recognised by the mainstream medical profession. That is not the case for food intolerances. The testing I do is testing for a definite reaction in the blood (IgG antibodies), but some practitioners in the medical profession claim that this measurement is not relevant. However, I have been doing food intolerance testing for my clients for a few years with very positive diagnostic results. Taking highly reactive foods out of the diet generally helps a wide range of conditions, especially irritable bowel syndrome, and multi system disorders such as chronic fatigue syndrome and fibromyalgia.

I decide which testing should be prescribed by looking at a client’s symptoms. If there is evidence of an allergy (permanently runny nose, itchy eyes, mucousy chest, skin rashes etc) I would definitely recommend allergy testing plus food intolerances (which can also be linked to all of these symptoms). However, if I have a client with IBS, IBD, headaches, gastric reflux etc I would be more likely to just test food intolerances. I can do food intolerance testing in the clinic via a blood spot test. The allergy and intolerance test requires a kit to be ordered and a blood draw to be taken. The results normally return in 4-5 weeks.

I have found both forms of testing to be excellent diagnostic tools and altering the diet to take into account a person’s individual food reactions can be the difference between feeling slightly unwell or chronic ill health and feeling amazing.


Fiona is one of my all time favourite people. After high school, I weighed in at 99kg. At 174cm, I have been overweight by 15-20 kgs for all my adult life. Until, at age 53, I met Fiona. She immediately diagnosed my primary problem and by following her dietary coaching, I lost 16 kgs in 5 months. More importantly, I have maintained this for more than a year now. Now, well into the second half of my life, life is good, very good. As I said, Fiona will always be one of my all time favourite people. Thank you Fiona.

Fiona ran a course at work and it was fantastic – I learned so much and she tailored the programs to each individual which worked really well. I reached my weight loss and health goals and it really wasn’t too hard and I still have treats!  More importantly, I feel much better in myself for making food changes and continued to see her independently when the course at work finished.
Charlotte Carlish
Indigestion, stomach pain and abdominal cramps, were an every day occurrence for me. I was quite desperate by the time I found Fiona. With the help of some supplements and allergy testing, Fiona Took me on a journey of discovery. Thanks to her professional and kind guidance, I now  know which foods to avoid and which ones will help my gut to stay healthy.  For the very first time in a long time, my tummy now feels quite normal and I no longer suffer any of the above conditions. To say Fiona has change my life may sound rather dramatic but it is completely true and I will be forever grateful to her.

Feeling Great, Losing Weight!

I have been working with Fiona at Physical Nutrition for about 10 weeks through a corporate program run my employer.  Losing weight and making some real changes to my dietary lifestyle has been a game changer for me.  Through her weekly tutorials, Fiona has taught me about the food I eat, what is best for my body and to gauge how I feel after each meal.  Combined with a sensible exercise routine of walking and cycling, I have managed to drop my weight by 7kgs during this period.  My energy levels are up, I’m feeling fitter and I’m eating much more balanced meals and now know which foods to avoid and which to eat more of!  It’s been a great experience and I would highly recommend Fiona’s program.

I have recently completed the Physical Nutrition 10kg in 20 weeks program and I couldn’t be more thrilled with the support and guidance Fiona has provided.
The 10 in 20 program not only helped me change my habits by giving me a coach that kept me accountable but also helped to educate me to make better nutrition choices in the future.
Thank you again Fiona & this is just the beginning, I’m not going anywhere ☺️
Paris Doran
Fiona has been working with the City of South Perth over the last year.  She has developed a customised 10 week health coaching and nutrition program with us which the City now offers as part of its suite of health and wellbeing benefits.  All of the participants were overwhelmingly positive about the program.  They rated the program highly on the aspects of Fiona’s professionalism, approachability and knowledge, as well as the results they had achieved.
I would recommend Physical Nutrition to any organisation looking to develop staff benefits.
Gillean Sharp
Physical Nutrition/Fiona Murray has really helped my husband and I to achieve our weight loss and lifestyle goals. Her advice, support and knowledge during the 20 week challenge has set us up to lead a healthier and balanced life style. We thought we had enough food and exercise knowledge before meeting Fiona but she has kept us on track, motivated us and through her group classes has kept us entertained and true to our goals! Thanks Fiona!
Alison Thair
My son is 21 and has been ill for years and part of it was Diet, and we have been to many nutritionalist’s but FIONA MAKES SENSE and TELLS YOU WHY you should be careful what you eat. She changed my sons life so I sent my Daughter who had auto immune issues and she has helped her. It is now my turn so I will keep you updated. Highly recommend her she is also very understanding.
Lisa Mann
I have been with Fiona at Physical Nutrition for several months in relation to skin and gut problems and for weight loss. Fiona is knowledgeable and supportive. I am slowly losing weight and my skin and gut issues are improving. Fiona works in conjunction with my integrative medical practitioner which is a very helpful. First time I have had any positive results, a slow but worthwhile approach.
Lynne Besant


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