Comparison of infant feeding patterns reported for nonindustrial populations with current recommendations.

The observation that young child-feeding practices rarely conform to current global recommendations is of major public health nutrition policy concern and raises questions about whether near-universal compliance with recommendations is feasible in any population. This analysis uses indicators of age at introduction of complementary foods and termination of breastfeeding available from ethnographic and demographic reports published between 1873 and 1998 to test the hypothesis that recent and contemporary nonindustrial societies practice patterns of infant feeding concordant with current global recommendations. Results suggest that ethnographically reported average ages at introduction of nonbreast milk liquids (4.5 +/- 6.0 mo) and solids (5.0 +/- 4.0 mo) and the duration of breastfeeding (29.0 +/- 10.0 mo) among a sample of 113 such populations concord with those at which key weaning transitions are biologically optimal for most normal healthy children. However, wide variation in estimates across populations remains unexplained and serious limitations in the available data preclude proper assessment of the underlying distribution of the timing of weaning transitions within populations.