Study	Reason for exclusion
Chapman 2016	Observational study, not controlled trial
DRKS00012842	Nutritional intervention around malnutrition, anaemia and vitamin A, no breastfeeding support described as being provided. Therefore not eligible for inclusion as not aimed at supporting mothers who are overweight or obese to breastfeed.
Lewkowitz 2018	Intervention was parent education along with enhanced lifestyle and breastfeeding support. This was compared against a standard parent education intervention. "The randomized control trial did not include a control group receiving routine prenatal care." Neither was the study comparing 2 different types of breastfeeding intervention. Therefore not eligible for inclusion.
NCT03640104	Dietary intervention in women who are breastfeeding. Intervention does not include breastfeeding support. BMI measured at recruitment (postpartum) not at booking. Therefore not eligible for inclusion.
Nicklas 2014	Pre‐pregnancy BMI 18‐40 kg/m², BMI measured at time of recruitment (postnatal) ≥ 24 kg/m² (or ≥ 22 kg/m² for Asian women). Therefore not eligible for inclusion.

BMI: body mass index