title: A longitudinal study of prolonged breastfeeding in relation to child undernutrition.
abstract: BACKGROUND
  In a number of studies prolonged breastfeeding was associated with a higher risk of undernutrition, although most of these studies are limited by their cross-sectional design which does not allow examination of temporal relationships between full weaning and undernutrition.
  
  
  METHODS
  The relationship between prolonged breastfeeding and child growth was examined prospectively among children under 36 months old who participated in a large cohort study. At baseline and at each of three 6-monthly follow-up visits breastfeeding status was assessed and all subjects were weighed and measured.
  
  
  RESULTS
  Undernourished children were more likely to be breastfed for a longer period of time compared with normal children. We found a small difference between breastfed and fully weaned children in the gain in height over the following 6-month period; however, breastfed children were likely to gain significantly less weight, particularly among children who were aged 6-12 months. Similar findings were noted when these associations were examined among children who were normally nourished at the time of breastfeeding assessment. The inverse association between breastfeeding status and weight gain was significantly larger among children of poor or illiterate mothers compared with children of relatively more affluent or literate mothers, respectively.
  
  
  CONCLUSIONS
  Our findings suggest that the inverse association is not causal, and may be explained by poorer complementary feeding among breastfed compared with weaned children. Children from poorer households and whose parents are illiterate are more likely to have less than adequate complementary feeding. The importance of adequate complementary feeding in the second half of infancy needs to be stressed in nutrition education programmes.
authors.affiliation: Department of Nutrition, Harvard School of Public Health, Boston, MA 02115, USA.
authors.forename: W W
authors.initials: WW
authors.lastname: Fawzi
authors.forename: M G
authors.initials: MG
authors.lastname: Herrera
authors.forename: P
authors.initials: P
authors.lastname: Nestel
authors.forename: A
authors.initials: A
authors.lastname: el Amin
authors.forename: K A
authors.initials: KA
authors.lastname: Mohamed
mesh_terms: D001827:Body Height; D001835:Body Weight; D001942:Breast Feeding; D002648:Child; D015362:Child Nutrition Disorders / Q000453:epidemiology / Q000209:etiology*; D002664:Child Nutritional Physiological Phenomena; D002675:Child, Preschool; D015331:Cohort Studies; D003906:Developing Countries; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007228:Infant Nutrition Disorders / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D009752:Nutritional Status; D011446:Prospective Studies; D013397:Sudan / Q000453:epidemiology; D013997:Time Factors