title: Breast-feeding and postpartum weight retention: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Weight gained during pregnancy and postpartum weight retention might contribute to obesity in women of childbearing age. Whether breast-feeding (BF) may decrease postpartum weight retention (PPWR) is still controversial. The purpose of our systematic review and meta-analysis was to investigate the relationship between BF and PPWR.
  
  
  METHODS
  Three databases were systematically reviewed and the reference lists of relevant articles were checked. Meta-analysis was performed to quantify the pooled standardized mean differences (SMD) of BF on PPWR by using a random-effect model. Heterogeneity was tested using the χ 2 test and I 2 statistics. Publication bias was estimated from Egger's test (linear regression method) or Begg's test (rank correlation method).
  
  
  RESULTS
  Among 349 search hits, eleven studies met the inclusion criteria for the meta-analysis. Seven studies were conducted in the USA, one in Brazil, one in France, one in Georgia and one in Croatia. Compared with formula-feeding, BF for 3 to ≤6 months seemed to have a negative influence on PPWR and if BF continued for >6 months had little or no influence on PPWR. In a subgroup meta-analysis, the results did not change substantially after the analysis had been classified by available confounding factors. There was no indication of a publication bias from the result of either Egger's test or Begg's test.
  
  
  CONCLUSIONS
  Although the available evidence held belief that BF decreases PPWR, more robust studies are needed to reliably assess the impact of patterns and duration of BF on PPWR.
authors.affiliation: Division of Nutrition and Food Hygiene,School of Public Health,Anhui Medical University,81 Mei Shan Road,Hefei 230032,Anhui,People's Republic of China.
authors.forename: Xiujie
authors.initials: X
authors.lastname: He
authors.affiliation: Division of Nutrition and Food Hygiene,School of Public Health,Anhui Medical University,81 Mei Shan Road,Hefei 230032,Anhui,People's Republic of China.
authors.forename: Meng
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Division of Nutrition and Food Hygiene,School of Public Health,Anhui Medical University,81 Mei Shan Road,Hefei 230032,Anhui,People's Republic of China.
authors.forename: Chuanlai
authors.initials: C
authors.lastname: Hu
authors.affiliation: Division of Nutrition and Food Hygiene,School of Public Health,Anhui Medical University,81 Mei Shan Road,Hefei 230032,Anhui,People's Republic of China.
authors.forename: Xingyong
authors.initials: X
authors.lastname: Tao
authors.affiliation: Division of Nutrition and Food Hygiene,School of Public Health,Anhui Medical University,81 Mei Shan Road,Hefei 230032,Anhui,People's Republic of China.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Li
authors.affiliation: Division of Nutrition and Food Hygiene,School of Public Health,Anhui Medical University,81 Mei Shan Road,Hefei 230032,Anhui,People's Republic of China.
authors.forename: Qiuwei
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Division of Nutrition and Food Hygiene,School of Public Health,Anhui Medical University,81 Mei Shan Road,Hefei 230032,Anhui,People's Republic of China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000328:Adult; D001942:Breast Feeding / Q000009:adverse effects; D015331:Cohort Studies; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D009765:Obesity / Q000209:etiology / Q000517:prevention & control*; D050177:Overweight / Q000209:etiology / Q000517:prevention & control*; D049590:Postpartum Period; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D015430:Weight Gain; D015431:Weight Loss
keywords: Exclusive breast-feeding; Formula feeding; Mixed feeding; Obesity; Postpartum weight retention