Koehler 2007.

Study characteristics
Methods	RCT
Participants	Study setting: Dortmund, Germany, including members of a nationwide compulsory health insurance company (NOVITAS Vereinigte BKK, Duisburg, Germany) who reported the birth of a baby Inclusion criteria: mother speaking German and available by telephone, as well as healthy term (> 37 weeks of pregnancy) infant with birth weight > 2500 g 183 mothers and infants were recruited: 142 (68 (48%) males) in the intervention group and 41 (22 (54%) males) in the control group
Interventions	Intervention group: nutrition counselling sessions via telephone hotline 3 times per week for 2 hours each time (Group 1), written information (Group 2), and personal telephone counselling (Group 3) Control group: no counselling
Outcomes	Food‐based and meal‐based dietary scores to evaluate infant's diet
Identification
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	This was not mentioned in the article
Allocation concealment (selection bias)	Unclear risk	This was not mentioned in the article
Blinding of participants and personnel (performance bias) All outcomes	High risk	Because of the nature of the intervention, parents in the intervention arm were not blinded
Blinding of outcome assessment (detection bias) All outcomes	High risk	Outcome assessment depended upon maternal recall of infant's diet, whereby the mother was not blinded to the intervention given
Incomplete outcome data (attrition bias) All outcomes	Low risk	All recruited infants completed the study
Selective reporting (reporting bias)	Low risk	All proposed outcomes were reported
Other bias	High risk	Only 37% and 54% of potential users used the telephone hotline and personal telephone counselling, respectively