Changes in body mass index on a gluten-free diet in coeliac disease: a nationwide study

The clinical presentation of coeliac disease has changed and patients are often overweight at diagnosis. There is concern that patients might gain further weight while on a gluten-free diet (GFD). The aim of the study was to evaluate the impact of a GFD on the body mass index (BMI) in a nationwide cohort of coeliac patients and to determine variables predictive of favourable or unfavourable BMI changes.

We prospectively investigated weight and disease-related issues in 698 newly detected adults diagnosed due to classical or extraintestinal symptoms or by screening. BMI at diagnosis and after one year on a GFD were assessed and compared with that in the general population.

At diagnosis, 4% of subjects were underweight, 57% normal, 28% overweight and 11% obese. On a GFD, 69% of underweight patients gained and 18% of overweight and 42% of obese lost weight; in the rest BMI remained stable. Changes were similar in both symptom- and screen-detected patients. The coeliac group had a more favourable BMI pattern than the general population. Favourable BMI changes were associated with subjects' self-rated expertise on GFD and young age at diagnosis, but not dietary counselling received.

BMI improved similarly in screen- and symptom-detected coeliac disease patients on a GFD.