Non celiac gluten sensitivity may explain digestive and general symptoms in patients without celiac disease but this recently described entity is controversial. The role of gluten in comparison to other nutriments such as saccharides and polyols (FODMAPs) remains debated. If a gluten-free diet is clearly indicated in celiac disease and wheat allergy, it remains debatable in non-celiac gluten sensitivity given weak and contradictory evidence. There is no strong evidence for a strict indication to a gluten-free diet in endocrinological, psychiatric, and rheumatologic diseases, or to improve performance in elite sports.