Food Intolerance

What is a food intolerance?

A food intolerance is defined as a non-immune mediated reaction to food. It involves the body’s systems responding to the food trigger with a range of symptoms of varying aetiology. Different food intolerances have different causes as to why your body can not properly digest or tolerate that certain food type. For example, individuals who are lactose intolerant cannot properly digest the lactose as the enzyme lactase cannot efficiently hydrolase the lactose or is not present.

Therefore, the lactose cannot be broken down into the monosaccharides glucose and galactose and remains in the intestine creating an osmotic force, moving water into the bowel. This increased water volume leads to bloating and abdominal cramps. From there, the lactose passes to the colon where fermentation occurs causing flatulence. The excess contents and fluid in the bowel causes diarrhoea.

For other types of food chemical intolerance, receptors in the lining of the gut may be triggered and cause pain, bloating and associated systemic symptoms. Some food chemical intolerances such as amine, salicylate or MSG intolerances can give rise to behavioural symptoms like irritability, headaches and skin symptoms like eczema, dermatitis or rashes.

Within Australia almost 4 million people avoid certain food types because of an allergy or an intolerance.

What causes a food intolerance?

The causes of food intolerance can be for many different reasons and specific to that certain intolerance. Some individuals may have secondary lactase deficiency which occurs due to damage of the cells that produce lactase caused by untreated inflammation of the digestive tract (commonly seen with coeliac disease). This type of intolerance can be reversed through eliminating lactose and reducing inflammation of the digestive system for a certain period of time and then slowly reintroducing it into the diet. Not all food intolerances are lifelong, some can be treated through dietary prescription and intervention.

Common foods that cause food intolerance symptoms include

Dairy products
Monosodium glutamate (MSG, additives numbers 621 and 625)
Vasoactive amines (Found in pineapples, bananas, baked meat, vegetables, red wine, wood-matured white wine, avocados, chocolate, citrus fruits and mature cheese)
Salicylates (found in herbs, spices, fruits and vegetables)
Toxins
Irritants (caffeine and chilli).
Food additives such as benzoate’s, sulphites and nitrates

Common food intolerance symptoms can include but are not limited to:

Nausea
Abdominal pain
Flatulence
Bloating
Vomiting
Heartburn
Diarrhoea
Headaches
Irritability or nervousness.
Sinus congestion
Bladder irritation
Skin reactions like rashes, hives
eczema, dermatitis

How can Bites Dietitians help?

Food intolerances can be difficult to diagnose. When diagnosing your food intolerance our Dietitians will ensure there is no other health condition or food allergy that could be causing these symptoms and refer you to appropriate other health professionals like a gastroenterologist or immunologist if they suspect there is something further to investigate additional to dietary factors. If they determine that diet or other lifestyle factors are causing these symptoms to occur, they will help you identify individual triggers that should be avoided. Based on your symptoms and current diet, our Dietitians will prescribe a type of elimination diet to investigate which foods could be triggering these symptoms. Once the food or foods have been identified, our Dietitians can work closely with you to establish dose thresholds and slowly reintroduce these foods back into your diet in a way that does not cause symptoms. It is likely that your body can cope with small amounts of these foods and the food can be incorporated back into your meal plan in amounts your body can tolerate. This means you might not have to completely avoid foods you are intolerant to.

Book an Appointment

An interesting fact about diet and food intolerances

In some individuals, symptoms of a food intolerance may occur up to 12-48 hours after the food has been consumed. Therefore, most people blame the last food they have eaten but it could actually be something they consumed 2 days ago! Due to this it’s really hard to self-diagnose food intolerance and best to complete any investigations under the guidance of an expert.

What improvement can you expect from tailored dietary prescription?

You can expect to have relief from uncomfortable symptoms of a food intolerance within 1 – 4 weeks of beginning an investigative elimination diet and/or tailored dietary prescription. You’ll get some clarity on what foods trigger your symptoms within the reintroduction phase which is typically within about 6 – 12 weeks of following the prescribed investigation protocol. Thereafter our dietitians can determine if smaller amounts of the foods you have positively reacted to can be tolerated. Most of our clients report that working with our Dietitians gives them a sense of “predictability” around their food intolerances, eg they know if they eat X then Y will happen rather than feeling uncertain about eating out or consuming particular foods. In summary, you can look forward to:

Diagnosis/identification of the food source(s) that trigger symptoms
Understanding of the mechanisms behind the food intolerance you have
Reintroduction of likely alot of foods back into your diet following clarification of the specific triggers
Limited to no symptoms following identification of food intolerances
Understanding the maximum amount of food your body can tolerate (threshold) without triggering symptoms.

How will you know it’s working/you’re improving ?

We will monitor your symptoms along the way and may ask you to measure and keep a record of your symptoms too in either a handwritten or phone app format so that you can clearly see your improvements.

Helpful things to bring/remember before your first appointment

Referral if you have one
Copies of any investigations you have already had done – including endoscopies, colonoscopies, blood tests, stool tests, breath tests, biopsies etc
A food diary if you have been keeping one with foods eaten and corresponding symptoms noted throughout (this is not necessary)
Medical history from your GP and/or treating specialists
List of medications and dosages.

Want To Know More About Other Conditions We Treat?

Learn More

Contact Details



305/29–31 Lexington Drive, Bella Vista NSW 2153



0452 458 146

