Dietary fibre intake in childhood or adolescence and subsequent health outcomes: A systematic review of prospective observational studies

Aim To determine whether higher fibre intakes during childhood or adolescence effect a broad range of intermediate markers of cardiometabolic risk or other health related issues. Materials and Methods We used online searches up to January 2020 and manual searches to identify prospective observational studies reporting on childhood or adolescent intakes of dietary fibre, vegetables, fruit and refined or whole grains. Outcomes measured later in life were body weight, blood lipids, blood pressure, glycaemia, bone health, cognition, growth and bowel habits. Potential age-specific ranges for dietary fibre were extrapolated from published adult data. Results We identified 45 publications reporting on 44 354 participants from 30 cohort studies. Mean age at dietary assessment varied from 1 to 19.3 years. Follow-up duration varied from 4 months to 27 years. Although well-conducted studies reported improvements in body weight, blood lipids and glycaemia, the diverse nature of studies precluded meta analysis. The quality of evidence was very low to low given the limited data available per outcome and the inability to synthesize results from multiple studies. Potential dietary fibre intake begins at 13-16 g a day for 2-year-olds and increases until the age of 10 years, when values are comparable with an adult range of 25-30 g a day. Conclusions Given the inconsistency in findings from cohort studies other than an absence of detrimental effects, it seems appropriate that recommendations regarding childhood fibre intake are extrapolated from relevant adult data.