Food Intolerance
Food intolerances can cause a wide range of symptoms and are not limited to digestive concerns. While some people experience bloating, abdominal pain or changes in bowel habits, others may notice symptoms affecting areas such as their skin, respiratory system, energy levels or general wellbeing.
There are many different types of food intolerance, and the foods or food components involved can vary considerably from person to person. Understanding your individual symptoms, diet and health history can help determine what may be worth investigating and guide an appropriate approach.
There are many different types of food intolerance, and the foods or food components involved can vary considerably from person to person. Understanding your individual symptoms, diet and health history can help determine what may be worth investigating and guide an appropriate approach.
What is a food intolerance?
Food intolerance occurs when a particular food or food component triggers unwanted symptoms after eating. Unlike food allergies, which involve the immune system, food intolerances generally do not involve an immune response.
Food intolerances can be dose-dependent, meaning you may tolerate a small amount of a particular food or food component but experience symptoms when you consume more than your individual tolerance level. Symptoms may also be delayed, sometimes appearing hours or even days after eating. This can make it difficult to identify which foods are contributing to your symptoms without a careful and systematic approach.
Food intolerances can be dose-dependent, meaning you may tolerate a small amount of a particular food or food component but experience symptoms when you consume more than your individual tolerance level. Symptoms may also be delayed, sometimes appearing hours or even days after eating. This can make it difficult to identify which foods are contributing to your symptoms without a careful and systematic approach.
What symptoms can food intolerances cause?
Depending on the type of intolerance, symptoms may include:
✓ Bloating, abdominal pain, wind or changes in bowel habits
✓ Reflux, nausea or digestive discomfort
✓ Headaches or migraines
✓ Fatigue, joint aches and body pains
✓ Mood changes, irritability, hyperactivity or difficulty concentrating
✓ Skin symptoms such as rashes, hives and eczema
✓ Sinus or respiratory symptoms, including exacerbation of asthma
✓ Other symptoms that appear consistently in association with particular foods
Different types of food intolerance
FODMAPs and carbohydrate intolerances: Some carbohydrates may be poorly digested or absorbed, resulting in digestive symptoms such as bloating, abdominal pain, wind and changes in bowel habits. Examples include lactose and fructose, as well as other FODMAPs that commonly trigger symptoms in people with IBS. Less commonly, deficiencies in digestive enzymes known as disaccharidases can affect the digestion of certain sugars and contribute to similar symptoms.
Food chemicals and additives: Some people experience symptoms associated with naturally occurring food chemicals such as salicylates, amines, glutamate and oxalates, or food additives including certain preservatives, colours and flavour enhancers such as MSG. These types of reactions are often investigated using a carefully structured elimination and food-challenge process.
Other food sensitivities: People may also report reactions to other naturally occurring components of foods or to particular individual foods. The evidence and mechanisms behind these reactions vary, so it's important to consider symptoms and health history carefully before unnecessarily restricting foods.
Food chemicals and additives: Some people experience symptoms associated with naturally occurring food chemicals such as salicylates, amines, glutamate and oxalates, or food additives including certain preservatives, colours and flavour enhancers such as MSG. These types of reactions are often investigated using a carefully structured elimination and food-challenge process.
Other food sensitivities: People may also report reactions to other naturally occurring components of foods or to particular individual foods. The evidence and mechanisms behind these reactions vary, so it's important to consider symptoms and health history carefully before unnecessarily restricting foods.
Investigating food intolerances
Identifying food intolerances can be challenging, particularly when symptoms are delayed, vary depending on the amount eaten, or several foods appear to be involved.
There is no single test that can diagnose all food intolerances. The most appropriate approach depends on the symptoms you are experiencing, your health history and the type of food intolerance suspected.
Depending on your individual circumstances, investigation may include:
There is no single test that can diagnose all food intolerances. The most appropriate approach depends on the symptoms you are experiencing, your health history and the type of food intolerance suspected.
Depending on your individual circumstances, investigation may include:
✓ Reviewing your symptoms, diet and health history
✓ Considering whether medical testing or further investigation may be appropriate
✓ Looking for patterns between particular foods and symptoms
✓ Using targeted elimination and structured food challenges where appropriate
✓ Identifying your individual tolerance levels rather than simply avoiding foods completely
✓ Ensuring your diet continues to meet your nutritional needs while foods are being investigated
The aim is to identify which foods or food components are genuinely relevant to you, while avoiding unnecessary long-term food restriction wherever possible.
The aim is to identify which foods or food components are genuinely relevant to you, while avoiding unnecessary long-term food restriction wherever possible.
The RPAH Elimination Diet
The Royal Prince Alfred Hospital (RPAH) Elimination Diet, sometimes referred to as the FAILSAFE diet, is a specialised elimination and food-challenge approach used to investigate suspected sensitivity to naturally occurring food chemicals and certain food additives.
I have experience supporting clients through the RPAH Elimination Diet, following training in this approach while working with the RPAH Allergy Unit in 2014.
This type of elimination diet is not necessary or appropriate for everyone. Where it is relevant, I can guide you through the elimination, food-challenge and reintroduction process while helping you maintain a varied diet and meet your nutritional needs.
I have experience supporting clients through the RPAH Elimination Diet, following training in this approach while working with the RPAH Allergy Unit in 2014.
This type of elimination diet is not necessary or appropriate for everyone. Where it is relevant, I can guide you through the elimination, food-challenge and reintroduction process while helping you maintain a varied diet and meet your nutritional needs.
How I can help
Investigating food intolerances is not always just about identifying foods to avoid. Depending on your symptoms and health history, it can also be valuable to consider your overall diet and nutrition, digestive health, and other health or lifestyle factors that may be influencing your symptoms or tolerance to foods.
My approach may also incorporate principles from the Gut Ecology & Metabolic Modulation (G.E.M.M) protocol, which draws on nutritional and nutrigenomic medicine alongside our understanding of gut microbiology, immune health and metabolism. Rather than automatically removing foods that appear to trigger symptoms, this approach aims to use nutritional and lifestyle strategies to support the underlying factors that may be influencing symptoms and food tolerance. Where appropriate, the preference is to maintain or build dietary diversity rather than unnecessarily restricting the diet.
My aim is to help you understand what may be contributing to your symptoms, identify which dietary changes are genuinely useful, and develop a plan that is as varied and flexible as possible.
Where food intolerances occur alongside IBS or ongoing digestive symptoms, I may also use my Gut Recovery Method to explore other factors that could be contributing to your gut symptoms and guide the most appropriate strategies for you.
My approach may also incorporate principles from the Gut Ecology & Metabolic Modulation (G.E.M.M) protocol, which draws on nutritional and nutrigenomic medicine alongside our understanding of gut microbiology, immune health and metabolism. Rather than automatically removing foods that appear to trigger symptoms, this approach aims to use nutritional and lifestyle strategies to support the underlying factors that may be influencing symptoms and food tolerance. Where appropriate, the preference is to maintain or build dietary diversity rather than unnecessarily restricting the diet.
My aim is to help you understand what may be contributing to your symptoms, identify which dietary changes are genuinely useful, and develop a plan that is as varied and flexible as possible.
Where food intolerances occur alongside IBS or ongoing digestive symptoms, I may also use my Gut Recovery Method to explore other factors that could be contributing to your gut symptoms and guide the most appropriate strategies for you.
Ready to take the next step?
If you have IBS alongside food intolerances, you can choose between the structured Gut Recovery Program or individual gut health consultations. If your concerns relate to food intolerances without IBS, individual nutrition consultations are also available.
Continue learning
If you'd like to learn more about IBS, gut health or how I can support you, these pages may be helpful.
Gut Recovery Program
Learn more about my structured program for people with IBS, including what's involved and the support you'll receive.
→ Explore the Gut Recovery Program
Irritable Bowel Syndrome (IBS)
Learn more about IBS, what can influence symptoms and the different approaches that may help.
→ Read about IBS
Gut Health
Explore the factors that can influence digestive health and how diet, lifestyle and other aspects of health can play a role.
→ Read about gut health
Learn more about my structured program for people with IBS, including what's involved and the support you'll receive.
→ Explore the Gut Recovery Program
Irritable Bowel Syndrome (IBS)
Learn more about IBS, what can influence symptoms and the different approaches that may help.
→ Read about IBS
Gut Health
Explore the factors that can influence digestive health and how diet, lifestyle and other aspects of health can play a role.
→ Read about gut health