Association of high dietary saturated fat intake and uncontrolled diabetes with constipation: evidence from the National Health and Nutrition Examination Survey

Background: Constipation is highly prevalent in the United States. The association of dietary fat intake with constipation has not been well studied. We recently reported that mice fed a high-fat diet had higher incidence of constipation than regular diet fed mice. The aim of this study was to assess if increased intake of dietary saturated fat in humans is also associated with higher risk of constipation and reduced stool frequency.

Methods: Analyses were based on data from 6207 adults (≥20 years) from the 2005-2006 and 2007-2008 cycles of the National Health and Nutrition Examination Surveys who had completed the bowel health questionnaire. Constipation was defined as a stool frequency of less than three times per week. Multivariable logistic regression analysis was used to calculate adjusted prevalence odds ratio (OR) estimates. Statistical analyses were performed using R and RStudio softwares.

Key results: The prevalence of constipation in this sample was 3.1%. After multivariable adjustment high saturated fat remained associated with constipation. The OR for high saturated fat intake associated with constipation was much higher in diabetics above 65 years, especially in non-Hispanic blacks, females, and those with poor glycemic control, compared to the control group.

Conclusions & inferences: To the best of our knowledge, this is the first report to investigate the association of high saturated fat diet, bowel frequency, and diabetes. This study demonstrates that a high dietary saturated fat intake is associated with significant increase in the prevalence of constipation, especially in the uncontrolled diabetic, non-Hispanic black, female patients.