Body mass index in celiac disease: beneficial effect of a gluten-free diet.

Background: There is concern about celiac disease patients being overweight and gaining more weight while on a gluten-free diet (GFD).
Aim: To investigate body mass index (BMI) and effect of GFD on BMI of celiac disease patients in the United States where obesity is a systematic problem.
Methods: BMI at diagnosis and after 2.8 years (mean) on a GFD were compared with national data.
Results: Among our patients (n=369, 67.2% female), 17.3% were underweight, 60.7% normal, 15.2% overweight, and 6.8% obese. All patients were followed by a dietitian. Compared with national data, females had lower BMI (21.9 vs. 24.2, P<0.0001) and fewer were overweight (11% vs. 21%, P<0.0001); more males had a normal BMI (59.5% vs. 34%, P<0.0001) and fewer were underweight (9.1% vs. 26.7%, P<0.0001). Factors associated with low BMI were female sex, Marsh IIIb/c histology, and presentation with diarrhea. On GFD, 66% of those who were underweight gained weight, whereas 54% of overweight and 47% of obese patients lost weight.
Conclusions: A GFD had a beneficial impact on BMI, underweight patients gained weight and overweight/obese patients lost weight. The improvement in BMI adds to the impetus to diagnose celiac disease. Expert dietary counseling may be a major factor in the beneficial effects we noted.