Table 1

Prospective association between frequency of hard stools at (1) 4 weeks and (2) 6 months and fibre intake at 2 years

	Unadjusted	Adjusted 1	Adjusted 2
	Beta (95% CI)	Beta (95% CI)	Beta (95% CI)
(1) Frequency of hard stools at age 4 weeks
Never	0.00 ref	0.00 ref	0.00 ref
Sometimes/occasionally	−0.215 (−0.268 to −0.162)	−0.051 (−0.109 to 0.008)	0.038 (−0.033 to 0.109)
Always	−0.479 (−0.677 to −0.281)	−0.229 (−0.445 to −0.013)	−0.111 (−0.331 to 0.109)
Omnibus p value	P<0.001	P=0.034	P=0.293
R²	0.012	0.0445	0.0488
N	6796	5249	5126
(2) Frequency of hard stools at age 6 months
Never	0.00 ref	0.00 ref	0.00 ref
Sometimes	−0.114 (−0.158 to −0.070)	−0.089 (−0.135 to −0.043)	−0.077 (−0.124 to −0.029)
Usually	−0.171 (−0.237 to −0.104)	−0.103 (−0.172 to −0.034)	−0.092 (−0.163 to −0.021)
Omnibus p value	P<0.001	P<0.001	P=0.003
R²	0.0036	0.0511	0.0558
N	9828	7550	7214

Estimates represent standardised differences in continuous measure of fibre intake relative to the group who are reported to never suffer from hard stools.
Adjusted 1: adjusted for sex, and sociodemographic variables (mother’s social class, based on the occupational social class classification dichotomised into non-manual (professional, managerial and skilled occupations) and manual (comprising partly skilled or unskilled professions); early parenthood indicating if the mother was under 19 years when giving birth to the study child; level of maternal education: <O-level (ie, no school leaving qualification), O-level (school leaving qualifications obtained at age 16 years) and A-level/degree (qualifications from further education); housing tenure: mortgaged/owned; privately rented; subsidised rented; and experience of material hardship (dichotomous variable); household income equivalised, a composite measure of disposable income split into quintiles.).
Adjusted 2: (1) further adjusted for breast/bottle feeding status in first 4 weeks/(2) further adjusted for breastfeeding duration in first 6 months and timing of introduction of both milk and solids.