Gluten-Free Diet

Early descriptions and the link to wheat

A short historical review traces celiac disease from Aretaeus of Cappadocia, in the first century A.D., to Willem Karel Dicke in the middle of the twentieth century. The same review notes that an intestinal disease with prominent malabsorption resembling celiac disease was described in India in the fifteenth century B.C. Only the abstract of this Czech-language review could be read, so the details of Dicke's observations are not reported here.

From a medical diet to a consumer product

A review of the diet's history states that, in the past, few gluten-free products were available, awareness of the diet was limited to the pediatric community, and most production took place in households. It reports that targeted screening improved celiac diagnosis, that the number of newly diagnosed patients who depend on the diet for life rose, and that production of gluten-free products increased with it. The same review says the diet was later adopted voluntarily by people with other diseases and by people without a medical reason, and expects its popularity to keep growing.

Recognition of gluten sensitivity without celiac disease

A 2021 narrative review describes non-celiac gluten sensitivity as a clinical entity that was recognized only recently. It notes that epidemiological studies of the condition have relied on self-report, and that the prevalence based on gluten challenge testing has not yet been estimated.

Celiac disease and dermatitis herpetiformis

The American College of Gastroenterology (ACG) guideline defines celiac disease as a permanent immune-mediated response to gluten present in wheat, barley and rye, characterized by small bowel injury and specific antibodies. The term is spelled coeliac in British usage. A 2023 dermatology review describes dermatitis herpetiformis as the cutaneous manifestation of celiac disease.

Non-celiac gluten or wheat sensitivity

Non-celiac gluten sensitivity (NCGS), also called non-celiac wheat sensitivity (NCWS), is described as reproducible symptoms after eating gluten-containing foods in people who have neither celiac disease nor wheat allergy. Reviews note that no reliable biomarker exists, so placebo-controlled gluten challenges are used for diagnosis in research. The Salerno Experts' Criteria are a challenge protocol that one review calls impractical for routine clinical use.

Related terms and neighboring pages

Gluten avoidance and GFD are short forms used in the research literature. FODMAPs are fermentable carbohydrates that a different dietary approach restricts, described on the Low-FODMAP Diet page. This page belongs to the Dietary Approaches family and does not cover the Anti-Inflammatory Diet, which makes separate claims. The professions that advise on diets are described on the Dietetics and Nutritional Therapy pages.

What the diet excludes

The ACG guideline states that current treatment for celiac disease requires strict adherence to a gluten-free diet and lifelong medical follow-up. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) explains that gluten can spread to gluten-free foods through contact during growing, processing, storage, preparation or serving, which is called cross-contact. This page does not give shopping lists or meal plans.

Follow-up and dietitian involvement

The NHS states that after a celiac diagnosis people are referred to a dietitian to adjust to the diet and to make sure it is balanced. NIDDK similarly describes a registered dietitian as able to help identify gluten and plan a balanced diet. The ACG guideline adds that patients whose symptoms persist on the diet need a systematic workup, in particular for unintentional gluten contamination.

Testing happens while eating gluten

NIDDK advises talking with a doctor about testing before starting the diet and states that avoiding gluten beforehand can make test results inaccurate. The ACG guideline describes serum antibody detection as helpful for initial screening and states that intestinal biopsy is required in most patients to confirm the diagnosis. The European pediatric guideline recommends total IgA with IgA antibodies against transglutaminase 2 as the initial blood tests and describes a no-biopsy pathway in selected children.

Established medical uses

The gluten-free diet is the treatment guidelines name for celiac disease. A 2023 review states that the therapy for wheat-sensitivity disorders, which it groups with celiac disease and dermatitis herpetiformis, consists of a wheat- or gluten-free diet. These are medical uses delivered with clinical diagnosis and follow-up.

Gluten or wheat sensitivity

For NCGS, a 2025 narrative review states that management primarily involves eliminating wheat and gluten, and that a low-FODMAP diet has also been used as an adjunct. Another review calls the evidence on the effectiveness of the gluten-free diet and the low-FODMAP diet controversial. The research section below sets out what trials found.

Wellness and weight loss

A review reports that gluten-free products came to be marketed as a weight loss diet with positive effects on health, and that the diet has been misinterpreted as a miracle drug effective on a variety of problems. The sources reviewed for this page report no controlled trial of the diet for weight loss or general wellness in people without a gluten-related condition.

Celiac disease

The ACG guideline states that most patients with celiac disease have an excellent clinical response to the diet. It defines nonresponsive celiac disease as persistent or recurrent symptoms despite the diet and calls refractory celiac disease a rare cause of nonresponse with a generally poor prognosis. The abstracts read here do not report randomized trials of the diet in celiac disease.

Double-blind trials in gluten sensitivity

In a double-blind crossover trial of 37 people with self-reported NCGS and irritable bowel syndrome, symptoms improved on a low-FODMAP diet and then worsened to a similar degree with gluten or with whey protein. Gluten-specific effects appeared in 8 percent of participants, and the authors found no evidence of specific effects of gluten. In a 59-person crossover trial, fructans caused more gastrointestinal symptoms than gluten.

An Italian crossover trial of 30 people with a prior irritable bowel diagnosis found that 46.1 percent met a gluten-response threshold under one scoring method and 19.2 percent under another. Its authors concluded that FODMAP intolerance can hide the response to a gluten challenge. A 2025 scoping review found 16 double-blind placebo-controlled studies, of which 8 reported a greater response to gluten than to control, and called the evidence inconsistent and the existing evidence insufficient to justify restricting specific components of wheat in NCWS.

Diagnosis, self-report and other conditions

A 2025 review reports that self-reported rates of NCWS often exceed 10 percent in the general population, while double-blind challenge studies confirm the diagnosis in typically fewer than 30 percent of cases. In an uncontrolled study of 142 people with fibromyalgia, 5.6 percent met the Salerno criteria and 21.8 percent responded to a six-week diet; the authors concluded the diet cannot be systematically recommended to all people with fibromyalgia.

People without celiac disease

A prospective cohort study followed 64,714 women and 45,303 men without known heart disease for 26 years. Long-term gluten intake was not associated with coronary heart disease risk after adjustment (hazard ratio 0.95 for the highest versus lowest fifth, 95 percent confidence interval 0.88 to 1.02). The authors noted that avoiding gluten may reduce intake of whole grains and concluded that promoting the diet among people without celiac disease should not be encouraged. This is observational evidence about gluten intake, not a trial of the diet.

Who sources advise testing before starting

NIDDK advises talking with a doctor about testing before starting the diet, because avoiding gluten beforehand can make celiac tests inaccurate. A person who stops eating gluten before assessment may therefore lose the ability to confirm celiac disease, which is a lifelong condition with its own follow-up. The sources reviewed do not quantify how often diagnosis is delayed this way.

Nutritional concerns

A meta-analysis of 38 studies with 2,114 people with celiac disease on the diet found high fat intake, low fiber in adults (about 18.9 g a day), and insufficient vitamin D across ages, with calcium, magnesium and iron low in adolescents. In 65 adults with self-reported gluten sensitivity on the diet, intakes of vitamin D, folic acid, calcium, iodine and iron were below recommendations. NIDDK notes that some packaged gluten-free foods contain more fat and sugar. The sources reviewed do not report on cost.

Contamination and heavy metals

Cross-contact is a named concern for people with celiac disease, and the ACG guideline lists unintentional contamination as a cause to check in nonresponsive disease. A 2023 review found that rice-based products are a relevant source of arsenic and other metals, and that people on the diet had higher arsenic and mercury levels in blood or urine, described as far from toxic levels. Whether the difference is biologically relevant remains unanswered.

Training and care boundaries

In the United States, the Commission on Dietetic Registration sets the requirements for the registered dietitian credential, including a graduate degree, an accredited nutrition program and accredited supervised practice. The sources reviewed contain no training standard specific to the gluten-free diet. Persistent symptoms, suspected celiac disease and diet choices for children call for assessment by a clinician, and the diet is not a substitute for diagnosis or prescribed care.