On the core claim (no benefit for the general population): The evidence supports it. Harvard Health states plainly that there is no compelling evidence that a gluten-free diet will improve health or prevent disease if you don't have celiac disease and can eat gluten without trouble . Peer-reviewed reviews concur that while evidence showing that the gluten-free diet has a positive impact on everybody's health is weak, people with specific gluten-related disorders may benefit from it .

On gluten itself being harmful to non-celiac people: The largest relevant cohort found no cardiovascular signal from eating gluten. In the BMJ study, adjusted analysis showed there was no significant association between gluten intake and coronary heart disease . Notably, the direction of concern ran the other way: after additional adjustment for intake of refined grains, estimated gluten consumption was associated with a lower risk of coronary heart disease , and avoidance of gluten can result in less consumption of healthy whole grains, which can also affect cardiac risk .

On the "changes almost nothing except price and taste" framing: This is where the evidence diverges from the claim. Product-composition studies repeatedly find gluten-free bakery items are nutritionally different, not equivalent. In a large product database, protein content was significantly lower in GF foods (5.8 g/100 g) than gluten-containing foods (8.6 g/100 g) , although energy content, carbohydrate, total fat, saturated fatty acids, fiber and sugar did not differ between GF and gluten-containing products . The Italian market analysis found the protein content of GF food is lower in all the categories . A Swedish bread-specific study found gluten-free bread had a lower Health Star Rating than gluten-containing bread (mean 3.5 vs. 3.8) and concluded gluten-free bread products were slightly unhealthier due to a lower protein content . Broader reviews note several GF foodstuffs contain more fat, including saturated, and salt, but less minerals and vitamins than their equivalent with gluten , and that going gluten-free without need carries detrimental effects, including loss of the dietary fiber and nutrient deficiencies.

On the "or a real sensitivity" qualifier: This category is less solid than the post implies. A pooled analysis of double-blind challenges found that only 38 of 231 NCGS patients (16%) showed gluten-specific symptoms, and 40% of these subjects had a nocebo response . A randomized crossover trial concluded that in individuals with self-reported non-celiac gluten sensitivity, fructans induced symptoms rather than gluten. Clinical reviews similarly note that gluten-free diets may benefit a subset of patients with IBS and suspected non-celiac gluten sensitivity; however, in the absence of celiac disease, symptom improvement is often attributed to fructan restriction and placebo effects rather than to gluten elimination itself .

On the two-condition framing: The medically recognized indications are broader than "celiac or sensitivity." Reviews list the gluten-free diet as treatment for celiac disease, dermatitis herpetiformis, gluten ataxia, wheat allergy, and non-celiac gluten sensitivity , with gluten-related disorders grouped as immune-mediated disorders including celiac disease, dermatitis herpetiformis, and gluten ataxia; allergic reactions, such as wheat allergy; and non-celiac gluten sensitivity .

On price: Supported. GF products were more expensive (overall 183%) in all regions and venues , and mass-market GF products were 139% more expensive than the wheat-based version of the same product .