The relationship between daily meal and snack frequency with irritable bowel syndrome (IBS) was less investigated in the literature. We aimed to evaluate this association with IBS symptoms.

A cross-sectional study.

This investigation was performed in Isfahan, a large province in the centre of Iran. Individuals were asked to complete a self-administered questionnaire to quantify the numbers of daily main meals (one, two or three), snacks (never, 1–2, 3–5 or >5) and the total of them (<3, 3–5, 6–7 or ≥8). IBS and its subtypes were diagnosed according to Rome Ш criteria.

General adults (n 4669, 2063 men and 2606 women).

The prevalence of IBS was 18·6 % in males and 24·1 % in females. Individuals consuming three main meals had 30 % decreased risk of IBS (OR 0·70, 95 % CI 0·52, 0·94) compared with those with one main meal in the crude model. After adjustments for all potential confounders this relation disappeared (OR 0·67, 95 % CI 0·43, 1·03). Gender-specified analysis revealed that women consuming three main meals per day had 32 % decreased likelihood of having IBS symptoms compared with one daily main meal takers (OR 0·68, 95 % CI 0·47, 0·99). This relation remained significant after adjustment for potential confounders (OR 0·56, 95 % CI 0·36, 0·89). A decreased likelihood of IBS in the highest category of main meal consumption compared with the lowest one was found in obese or overweight subjects (OR 0·54, 95 % CI 0·32, 0·91), after adjustment for all confounders.

Our findings suggested that there was no significant relation between main meal or snack frequency and IBS in Iranian adults, but a small inverse association was found among females and overweight/obese individuals in subgroup analysis. Further prospective studies are needed confirming these associations.