Although only 1% of the population has been diagnosed with a gluten allergy, one out of every four Americans has adopted a gluten-free or reduced-gluten diet. However, a recent study performed at the Oslo University Hospital suggested that it may not be the gluten causing problems.

In the study, a muesli bar full of the carbohydrate fructan caused more problems than a bar of gluten, suggesting to researchers that fructan is the true cause of “gluten sensitivity.” As many wheat products contain fructan, there's a reason for confusion, and when patients eliminate gluten from their diets, they also eliminate fructan because it is present in wheat, spelt, rye, and barley.

The trouble with going gluten-free is that people end up eliminating foods from their diets unnecessarily with less improvement than they would get otherwise. To see if you have fructose sensitivity, monitor how you feel when you eat high-fructan, low-gluten foods like watermelon, bananas, prunes, onions, shallots, garlic, and Brussels sprouts.