Ahn 1980.

Methods	Design: retrospective cohort. Quality assessment Control for confounding: B. Follow‐up: C. Blinding: A for weight, B for length.
Participants	96 healthy U.S. infants living in Baltimore‐Washington area who were EBF for at least 6 months.
Interventions	EBF = BF with no solids or liquids other than human milk for > 6 months (n = 50). MBF = EBF for <= 6 months, then MBF until > 6 months (n = 46).
Outcomes	Weight and length gain in first 12 months.
Notes	1. No quantitative data provided. 2. Data requested on weight and length gain and illnesses in first year.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	D ‐ Not used