Myths vs facts: tTG IgA and weight loss

The tTG IgA test (tissue transglutaminase IgA) is a well-established serological marker for diagnosing celiac disease, an autoimmune condition triggered by gluten. Untreated celiac disease can lead to weight loss due to intestinal damage and malabsorption. However, the test is not a weight loss tool. In individuals without celiac disease or gluten sensitivity, tTG IgA provides no useful information for weight management. Marketing this test as a 'weight loss tool' is misleading. The evidence linking tTG IgA to weight loss is indirect: in untreated celiac disease, a gluten-free diet can normalize weight, but the test itself has no predictive value for weight loss in healthy individuals. Caveat: a positive tTG IgA should always be confirmed by duodenal biopsy before starting a gluten-free diet. False positives can occur (e.g., in other autoimmune diseases).