Relationship between body mass index, diet, exercise and gastro-oesophageal reflux symptoms in a community

Background: Body mass index (BMI) is a risk factor for gastro-oesophageal reflux but may simply be explained by diet and lifestyle. Aim: We aimed to determine the contribution of BMI. diet and exercise to GER. Methods: Community subjects (n = 211, mean age = 36 years, 43% males) completed validated questionnaires on gastro-oesophageal reflux, energy expenditure (Harvard Alumni Activity Survey), dietary intake (Harvard Food Frequency Questionnaire) and measures of personality and life event stress. Diet, exercise, BMI and other potential risk factors for reflux were analysed using logistic regression analyses. Results: The overall mean (±s.d.) BMI was 26.6 (±5.7); 79 (37%) reported infrequent (<weekly) reflux and 16 (8%) reported frequent (≥weekly) reflux. The median caloric intake was 2097 cal/day and the median daily energy expenditure was 1753 cal/day. Among those with BMI > 25, 10% reported frequent reflux compared to 4% of those with BMI ≤ 25. In a model which included age, sex and Symptom Checklist-90 somatisation T-score, BMI was associated with reflux (OR per 5 units = 1.9, 95% CI: 1.2, 3.0). In models which included diet and exercise variables, BMI but not diet or exercise was associated with reflux. Conclusion: BMI may be associated with symptomatic gastro-oesophageal reflux independent of diet and exercise.