But if you've been harbouring suspicions that some of your friends claiming to be allergic to gluten aren't being totally truthful, you could be right.
Although the number of people banishing gluten from their diets is rising, the prevalence of coeliac - or celiac to readers in the US - appears to have remained stable in recent years, according to an article published in the JAMA Internal Medicine journal.
And while there are an estimated 1.76m people with coeliac disease, there are 2.7m people who adhere to a gluten-free diet even though they don’t have coeliac disease in the US.
Coeliac disease is not connected to a gluten allergy at all - it's caused by the immune system mistaking substances found in gluten as a threat to the body.
The immune system then attacks healthy tissue, leading to digestive issues, which is why people suffering from coeliac avoid eating gluten. A pill to help stop gluten intolerance is in the works.
Scienctists in the US analysed data from the National Health and Nutrition Examination Surveys which found that while the prevalence of coeliac disease appears to have remained steady overall, at 0.7 per cent in 2009-2010, 0.77 per cent in 2011-2012 and 0.58 per cent in 2013-2014, adherence to a gluten-free diet by people without coeliac disease has increased over time, from 0.52 per cent in 2009-2010, to 0.99 per cent in 2011-2012 and 1.69 per cent in 2013-2014.
The scientists concluded that the growing interest in a gluten-free diet by people without coeliac disease could be due to a variety of factors, including public perception that it may be healthier, the growing availability of gluten-free products, and a self-diagnosis of gluten sensitivity by some individuals.