The number of people in the UK diagnosed with coeliac disease has risen from 24% in 2011 to 30% in 2015, according to new figures from Coeliac UK.
The charity, which provides support for people who need to live gluten free, carried out a search of UK patient records up to and including 2015.
As well as being concerned about the rise, it says it was also alarmed that the rate of diagnosis was slowing significantly, resulting in around half a million people in the UK still living with undiagnosed coeliac disease.
Coeliac disease is a serious autoimmune condition caused by a reaction to gluten, a protein found in wheat, barley and rye. People diagnosed with coeliac disease must maintain a strict gluten free diet for the rest of their life if they are to avoid very serious complications such as osteoporosis, infertility and although rare, small bowel cancer.
According to the charity, it still takes 13 years on average for a person with coeliac disease to be diagnosed.