The association of gastrointestinal symptoms with weight, diet, and exercise in weight-loss program participants

Background & Aims: Studies on the relationship between gastrointestinal (GI) symptoms and obesity are limited. Research on the relationship between GI symptoms (including irritable bowel syndrome [IBS]), weight, and weight-related behaviors are rare. This study assessed rates of GI symptoms in a sample of obese patients in a weight-loss program and explored relationships among GI symptoms and obesity, binge eating, dieting (fat and fruit/fiber consumption), and physical activity. Methods: A total of 983 participants (70% women) had a mean body mass index (BMI) of 33.2 ± 5.7 kg/m² (range, 25.1-60.8 kg/m²) and a mean age of 52.7 ± 12.4 years (range, 20.4-89.8 y). Participants completed a questionnaire about diet and physical activity and a standardized self-report Rome II questionnaire assessing IBS status and GI symptoms. Results: In bivariate analyses BMI was associated positively with abdominal pain and diarrhea whereas healthier diet (lower fat and higher fruit/fiber intake) and higher physical activity were associated with fewer GI symptoms. In multivariate models BMI was not associated with GI symptoms; physical activity remained a protective factor. Conclusions: Although physiologic mechanisms still need to be explored, associations between GI symptoms and diet and exercise behaviors may have implications for the treatment of both obesity and GI symptoms.