When and how to follow a gluten-free diet

Gluten is a protein found in wheat, barley and rye, and consequently, is found in many foods eg beer, biscuits, bread, cake, certain sauces, pasta and ready meals. However, even in foods made without wheat, barley or rye, gluten can still be present due to cross-contamination during food production eg oats are often contaminated with trace amounts of gluten. 

If your digestive system is sensitive to gluten, you will, therefore, need to take extra care to avoid foods made with gluten-containing ingredients but also foods that could be contaminated with gluten.

When to follow a gluten-free diet

Coeliac disease

If you are diagnosed with coeliac disease — an autoimmune condition where your immune system reacts adversely to gluten and consequently attacks your digestive system — you will need to follow a strict, gluten-free diet for the rest of your life. 

Symptoms of coeliac disease often overlap with other gastrointestinal conditions, such as irritable bowel syndrome (IBS), and include abdominal bloating and pain, loose stools and unintentional weight loss. Non-digestive symptoms include anaemia, brain fog, dizziness and fatigue, and in rare cases, pins and needles which could be related to low vitamin B12 levels or can occur without vitamin deficiencies.

A blood test for specific antibodies produced during coeliac disease can help determine whether you have the condition and should, therefore, switch to a gluten-free diet. 

If your blood test comes back positive, you will be referred to a doctor specialising in treating the gut (a gastroenterologist) for an intestinal biopsy. A thin telescope-like tube with a light and camera on the end (endoscope) will be passed via your mouth into your small intestine, so that a tissue sample can be collected for testing via a special tool passed through the endoscope. 

An intestinal biopsy can confirm your diagnosis of coeliac disease and determine its severity. If you have a parent with coeliac disease your risk of also having the disease is around one in 10. 

Other conditions

If you have IBS or a gluten intolerance, where you have symptoms of coeliac disease that come on after eating gluten but subsequent tests come back negative, you may also benefit from following a gluten-free diet.

However, you should always see a doctor before starting a gluten-free diet so you can rule out other causes of your symptoms, and receive a clear diagnosis and appropriate support. Following a gluten-free diet will limit your food choices so you will need to take extra care to ensure your diet remains healthy and balanced.

If you have a gluten intolerance or IBS and your symptoms improve, you may not need to follow a gluten-free diet for the rest of your life.

Advice for following a gluten-free diet

You can get all the vitamins and nutrients your body needs to remain healthy when following a gluten-free diet. However, it is important to note that some gluten-free products are higher in calories than their gluten-containing equivalents. Consequently, you should pay attention to how much you eat and match the calorie intake needs of your body to avoid excess weight gain.

Some weight gain when switching to a gluten-free diet is, however, common. This is because before diagnosis, while eating a gluten-containing diet, your gut lining is damaged and doesn’t properly absorb the food you’ve eaten. Once you switch to a gluten-free diet, your gut lining heals and can absorb everything, ensuring you get more nutrients and calories from your diet.

Once you reach a healthy weight, it is, therefore, important to keep a close eye on the sugar and calorie levels in your food to avoid becoming overweight.

Supplements are not usually needed on a gluten-free diet as your healed gut lining will be able to absorb all of the vitamins and nutrients you need (eg iron, vitamin B12, folate). If supplements are needed, this is usually only during the initial period after diagnosis of severe coeliac disease to help get your vitamin and nutrient levels quickly back up to healthy levels.

Living with coeliac disease

Once you have received a diagnosis of coeliac disease, you will be referred to a dietitian. They can help you adjust to a gluten-free diet, with meal plans, information of which foods to avoid and how to maintain a healthy, balanced diet.

Your condition will be monitored at least once a year to check on your symptoms, your weight, bone health, vitamin levels and how you are managing your dietary requirements.

In children with coeliac disease, their height will also be measured to ensure they’re growing in line with what is healthy for their age.