A plate with a spinach omelette, cherry tomatoes and slices of gluten-free bread

Coeliac disease, dermatitis herpetiformis

Strict Gluten-Free Diet

The only treatment for coeliac disease — and it has to be absolute.

Core restriction: Wheat, barley, rye and cross-contamination
Difficulty: ●●●●●
Check a food: Open the food checker

A gentle reminder. This guide is for learning, not a prescription. Therapeutic diets interact with medication and conditions, so it's worth talking to your doctor or a registered dietitian before you begin.

Download this guide as a PDF Open the printable version

A tidy few pages with the food lists, meal plan and reminders — good for the fridge door or the first appointment with your dietitian.

How it works

In coeliac disease, gluten peptides trigger an immune attack on the lining of the small intestine. Villi flatten, absorption fails, and the consequences run well beyond the gut: anaemia, osteoporosis, infertility, neuropathy and a raised risk of small bowel lymphoma.

There is no threshold of 'a little is fine'. Damage occurs at around 10-50 mg of gluten per day, which is roughly one crouton or a few crumbs from a shared toaster.

Non-coeliac gluten sensitivity is a different, real but less well-defined condition where trace exposure matters far less. The distinction determines how strict you need to be, which is why testing before going gluten-free matters.

Nutrition at a glance

For coeliac disease this is a lifelong medical treatment with a measurable contamination threshold.

Certified gluten-free: Under 20 ppm; The legal and clinical threshold
Damaging dose: ~50 mg gluten/day; About an eighth of a slice of bread
Gut healing: 6-24 months; Slower in adults than children
Follow-up bloods: 3, 6 and 12 months; Then annually
Fibre: 25-30 g/day; Gluten-free substitutes are usually low in it

Nutrients that often run short

Fibre
Iron
Folate
B12
Calcium
Vitamin D
Zinc

These are the ones worth planning for — through food where you can, and through a supplement your clinician suggests where you can't.

A word on electrolytes

Any change in how you eat changes how much sodium, potassium and magnesium you take in — usually downwards, because cooking from scratch removes the packaged foods that supplied most of it. Headaches, cramps, lightheadedness on standing and that flat, foggy feeling in the first fortnight are far more often an electrolyte dip than the diet failing. Drink to thirst rather than to a rule, salt your food unless you have been told not to, and lean on potassium- and magnesium-rich whole foods.

Sodium, potassium and magnesium are the three that matter most day to day. If you have kidney disease, heart failure or high blood pressure, or you take a diuretic, ACE inhibitor or ARB, set your targets with your clinician rather than with a supplement label — and avoid potassium-based salt substitutes unless you have been told they are safe for you.

Key cautions

None of this is meant to frighten you off. These are simply the things that most often catch people out on this diet — the ones worth raising at your next appointment.

Talk to a clinician
Never go gluten-free before coeliac testing
Serology and biopsy both normalise off gluten, and getting a diagnosis afterwards means a six-week gluten challenge that most people find miserable.
Worth testing
Bone density and nutrient status
Untreated coeliac disease costs bone. A DEXA scan and iron, folate, B12, vitamin D and calcium checks are part of standard follow-up.
Keep an eye on
Cross-contamination is the usual reason for ongoing symptoms
Shared toasters, colanders, fryer oil, wooden spoons and flour dust in the air all carry enough gluten to matter.
Keep an eye on
Gluten-free is not automatically healthier
Many substitutes are refined starch with more sugar and fat and less fibre than what they replace. Naturally gluten-free whole foods do better.

Used for

Coeliac disease
Dermatitis herpetiformis
Gluten ataxia
Non-coeliac gluten sensitivity, at a less strict level
Wheat allergy, which additionally excludes wheat-derived non-gluten proteins

What to eat

Eat freely

Naturally gluten-free staples

Rice
Corn and polenta
Potato
Quinoa
Buckwheat
Millet
Certified gluten-free oats
Legumes

Whole foods

All fresh meat, fish and eggs
Fruit and vegetables
Plain dairy
Nuts and seeds
Oils

Eat with care

Check the label every single time

Oats — only certified gluten-free; standard oats are cross-contaminated
Soy sauce, which is usually brewed with wheat — use tamari
Processed meats, stock cubes and gravy
Beer labelled 'gluten-removed' rather than gluten-free
Medications and supplements using wheat starch as an excipient
Communion wafers, playdough and lipstick

Best to skip

Gluten grains

Wheat in every form — durum, semolina, spelt, farro, kamut, einkorn
Barley and malt
Rye
Triticale
Brewer's yeast

Hidden sources

Malt vinegar and malt extract
Standard soy sauce
Seitan
Battered and crumbed food
Thickened sauces
Bulgur and couscous

Cross-contamination

Shared toasters
Shared fryer oil
Shared butter and spreads with crumbs
Bulk bins
Flour dust in a shared kitchen

Three days of meals

Day 1

Breakfast: Certified GF oats with milk and berries.
Lunch: Rice bowl with grilled chicken, avocado, black beans and salsa.
Dinner: Steak, baked potato, roasted broccoli.
Snack: Apple and peanut butter.

Day 2

Breakfast: Eggs with corn tortillas and cheese.
Lunch: Big salad with quinoa, chickpeas, feta and olive oil.
Dinner: Chicken curry with rice, using a checked GF curry paste.
Snack: Greek yoghurt with honey.

Day 3

Breakfast: Buckwheat pancakes with maple syrup.
Lunch: Rice noodle pho with beef and tamari.
Dinner: Roast salmon, polenta, green salad.
Snack: Corn chips and guacamole.

Getting started

1
Get tested before you stop eating gluten. Coeliac serology and biopsy both go negative on a gluten-free diet, and getting a diagnosis afterwards requires a miserable gluten challenge.
2
De-gluten the kitchen: separate toaster, separate colander, separate butter, replace scratched wooden and plastic utensils.
3
Ask for a coeliac dietitian and a bone density scan; deficiency in iron, B12, folate, vitamin D and calcium is common at diagnosis.
4
Learn the restaurant script: coeliac disease, medical, cross-contamination, separate preparation.
5
Screen first-degree relatives. Coeliac disease runs in families at roughly 1 in 10.

Common mistakes

Going gluten-free before testing.
Assuming gluten-free means healthy — GF processed food is often higher in sugar, fat and refined starch, and lower in fibre and B vitamins.
Eating oats that are not certified.
Missing malt, soy sauce and stock cubes, the three classic hidden sources.
Relaxing after symptoms improve. Silent damage continues without symptoms in many people.

FAQs

How strict is strict?

For coeliac disease, absolute. Around 10-50 mg of gluten a day — crumbs — is enough to cause measurable intestinal damage.

Is sourdough safe?

No. Long fermentation lowers gluten content but does not eliminate it. Wheat sourdough is not safe in coeliac disease.

What about 'may contain traces'?

Certified gluten-free products must be below 20 ppm. Precautionary 'may contain' labelling is not tested, so most coeliac dietitians advise avoiding it.

Stacking with other diets

Gluten-free is a permanent requirement, so every other diet on this site has to be built on top of it, not alongside it.
Gluten-free plus low FODMAP is straightforward and often used together for IBS-like symptoms that persist after diagnosis.
Keto and AIP are already gluten-free by construction.

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