Abstract:
Few studies investigated the associations between energy intake at each meal and defecation. Many studies have shown that having dietary fiber prevents constipation, but the results of these studies are inconsistent. The aim of this study is to clarify the associations between energy intake at each meal and food groups containing dietary fiber and the defecation, especially frequencies of bowel movement (BM) and stool forms.
We conducted a cross-sectional study of questionnaire and dietary surveys among students in Japan from May 2018 to May 2024. We divided 437participants (88: male, 349: female)into 3 groups according to the frequency of BM, and performed multinomial logistic analyses using 3 or 4 times BM per week (low), and less than twice BM per week (very low) versus 5 or more times BM per week (normal) as the outcome, with energy and food groups containing dietary fiber as the main explanatory variables. The Bristol stool form scale (BSFS) was used to judge the condition of the stool, and BSFS 1 and 2 were classified as the hard stool ,3-5 as the normal stool, and 6 and 7 as the diarrhea stool. We performed binomial logistic analyses using the hard stool versus the normal stool as the outcome, with energy and food groups containing dietary fiber as the main explanatory variables.
In males, higher breakfast energy intake was inversely associated with low frequency of BM. A cut off point for breakfast energy intake was 251 kcal [sensitivity=77%; specificity=85%; area under the curve=0.76]. In females, no significant associations were observed between energy intake and frequency of BM. In females, higher vegetable intake was inversely associated with very low frequency of BM. In males, no significant associations were observed between food groups containing dietary fiber and frequency of BM. There were no significant associations between energy intake and food groups containing dietary fiber and stool forms in both males and females.
