Bibliography	Tier	Study design	Study name	Food	Endpoint assessed	Additional comments
Gupta et al. ( 2017 )	1	RCT	n/a	CF	WAZ Attained body weight L(H)AZ Attained body length (height) HCZ Attained HC BMIZ Attained BMI BMD Lean + BMC mass % fat mass Fat mass Total cholesterol HDL‐cholesterol LDL‐cholesterol VLDL‐cholesterol Triglycerides Systolic blood pressure Diastolic blood pressure Iron status
Morgan et al. ( 2004 )	3	PA	n/a	CF	Attained body weight Weight gain Attained body length Length gain HC gain Subscapular SFT gain Triceps SFT gain Asthma‐like symptoms Eczema Sleep GI infections LRTI	No PE No PE No PE No PE No PE No PE
Spiegler et al. ( 2015 )	3	PC	German Neonatal Network (GNN)	CF	WAZ Attained body weight L(H)AZ Attained body length (height)	CV
Yrjänä et al. ( 2018 )	3	RETRO: CC	n/a	CF	Eczema ‐ Timing of introduction of CFs in cases and controls	No PE (eczema)
					Food allergy ‐ Timing of introduction of CFs in cases and controls

BMC: bone mineral content; BMD: bone mineral density; BMI: body mass index; BMIZ: body mass index‐for age z‐scores; CC: case–control study; CF: complementary food; CV: timing of introduction of complementary foods used as a continuous variable in the analysis; GI: gastrointestinal; HC: head circumference; HCZ: head circumference‐for‐age z‐scores; HDL: high density lipoprotein; LDL: low density lipoprotein; L(H)AZ: length (height)‐for‐age z‐scores; LRTI: lower respiratory tract infections; n/a: not applicable; PA: pooled analysis; PC: prospective cohort study; PE: point estimate; RCT: randomised controlled trial; RETRO: retrospective study; SFT: skin fold thickness; VLDL: very low density lipoprotein; WAZ: weight‐for‐age z‐scores.