Gastrointestinal conditions and restrictive diet

The medical diagnosis of gastrointestinal conditions was self-reported (‘have you ever been told by a doctor that you have…’) and included GORD, IBS, Crohn’s disease, ulcerative colitis and coeliac disease.

The current use of some restrictive diet included avoidance of milk/dairy products (‘Do you restrict your consumption of milk or dairy (lactose) products’), gluten (‘Do you avoid products containing gluten (wheat)’) and/or other foods causing pain, bloating and/or diarrhoea (‘Do you avoid certain foods because they cause pain, bloating or wind’).

Two binary (yes/no) variables were generated based on the previous information: (1) positive for any of the investigated gastrointestinal conditions and (2) current use of some restrictive diet.