Nutritional quality and costs of gluten-free products: a case-control study of food products on the Norwegian marked.

Background: Celiac disease is a chronic autoimmune disease triggered by gluten exposure in genetically predisposed individuals. A life-long intake of a gluten-free (GF) diet is required for its management. Wheat, rye and barley are eliminated in a GF diet and the nutritional adequacy of the diet has been questioned. In Norway, cereals and bread constitute a key role of the diet and are the main source of fiber intake. Gluten restrictions may therefore offer important implications for nutrient adequacy especially linked to fiber intake in people with celiac disease.

Objective: The aim of the study was to investigate the nutritional quality and price of GF products and compare with gluten-containing counterparts available at instead of in the Norwegian market.

Design: The macronutrient content of 423 unique GF products were compared with 337 equivalents with gluten. All products were selected from grocery stores and web-based shops, with the aim of including as many GF products as possible. Listed macronutrients content and price in 11 different food categories were compared to gluten-containing counterparts with Wilcoxon signed rank test.

Results: The GF products contained less protein and fiber, and higher content of saturated fat, carbohydrate and salt compared to the gluten-containing products. The total amount of fat was not different between the groups. A similar pattern was found within several of the food categories. More gluten-containing products met the nutrition claim "high in fiber" (fiber > 6 g/100 g) compared to the GF products. The price of the GF products was higher; ranging from 46%-443% more expensive than the gluten-containing products.

Conclusion: GF products are less nutritious and have a higher price compared to equivalent gluten-containing products. Knowing that an unhealthy diet is the most important risk factor for developing non-communicable diseases, the nutritional quality of a GF diet needs to be addressed and should be improved.