More than 19,000 people in the Horsham area are thought to suffer from coeliac disease and gluten intolerance.
The disease - an autoimmune condition triggered by an intolerance to gluten - can result in serious complications if left untreated.
Now awareness of the disease is being highlighted by the gluten-free food brand Schär which is urging anyone who thinks they have the disease to seek advice.
The firm is staging a roadshow today (Tuesday) at Tescos in Broadbridge Heath, between 10am and 5pm.
In the UK, the condition affects 1 per cent of the population, however, less than a quarter of those believed to have the condition have been clinically diagnosed. In addition, 13 per cent of the UK population could be living with an intolerance to gluten; also known as non-coeliac gluten sensitivity.
In Horsham this equates to an estimated 1,359 people living with coeliac disease and up to 17,663 with an intolerance to gluten.