Evolutionary anthropological and ethnographic studies are used to develop a general conceptual framework for understanding prehistoric, historic, and contemporary variation in human lactation and complementary feeding patterns. Comparison of similarities and differences in human and nonhuman primate lactation biology suggests humans have evolved an unusually flexible strategy for feeding young. Several lines of indirect evidence are consistent with a hypothesis that complementary feeding evolved as a facultative strategy that provided a unique adaptation for resolving tradeoffs between maternal costs of lactation and risk of poor infant outcomes. This evolved flexibility may have been adaptive in the environments in which humans evolved, but it creates potential for mismatch between optimal and actual feeding practices in many contemporary populations.

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.

Previously published data from our group and others demonstrate that human milk oligosaccharide (HMOs), as well as milk and infant fecal microbial profiles, vary by geography. However, little is known about the geographical variation of other milk-borne factors, such as lactose and protein, as well as the associations among these factors and microbial community structures in milk and infant feces. Here, we characterized and contrasted concentrations of milk-borne lactose, protein, and HMOs, and examined their associations with milk and infant fecal microbiomes in samples collected in 11 geographically diverse sites. Although geographical site was strongly associated with milk and infant fecal microbiomes, both sample types assorted into a smaller number of community state types based on shared microbial profiles. Similar to HMOs, concentrations of lactose and protein also varied by geography. Concentrations of HMOs, lactose, and protein were associated with differences in the microbial community structures of milk and infant feces and in the abundance of specific taxa. Taken together, these data suggest that the composition of human milk, even when produced by relatively healthy women, differs based on geographical boundaries and that concentrations of HMOs, lactose, and protein in milk are related to variation in milk and infant fecal microbial communities.

Behavior change communication (BCC) to improve health and caring practices is an integral component of efforts to improve maternal, newborn and child health (MNCH). Mobile phones are widely available in low- and middle-income countries (LMIC), presenting new opportunities for BCC delivery. There is need for delivery science to determine how best to leverage mobile phone technology for BCC to improve MNCH practices. We conducted a scoping review of studies and project reports documenting the feasibility, implementation or effectiveness of using mobile phones for BCC delivery related to MNCH in LMIC. Data were extracted and synthesized from three sources: i) systematic search of three electronic databases (PubMed, MedLine, Scopus); ii) grey literature search, including mHealth databases and websites of organizations implementing mHealth projects; iii) consultation with researchers and programme implementers. Records were screened using pre-determined inclusion criteria and those selected were categorized according to their primary intervention delivery approaches. We then performed a descriptive analysis of the evidence related to both effectiveness and implementation for each delivery approach. The systematic literature search identified 1374 unique records, 64 of which met inclusion criteria. The grey literature search added 32 records for a total of 96 papers in the scoping review. Content analysis of the search results identified four BCC delivery approaches: direct messaging, voice counseling, job aid applications and interactive media. Evidence for the effectiveness of these approaches is growing but remains limited for many MNCH outcomes. The four approaches differ in key implementation elements, including frequency, length and complexity of communication, and potential for personalization. These elements influence resource allocation and are likely to impact effectiveness for BCC targeting complex, habitual MNCH practices. This scoping review contributes to the evidence-base on the opportunities and limitations of using mobile phones for BCC delivery aiming to improve MNCH practices. The incorporation of mobile phone technology in BCC interventions should be guided by formative research to match both the content and delivery approach to the local context. We recommend five areas for further research, including both effectiveness and implementation studies on specific delivery approaches.

The mental health of caregivers has been shown to be important for improving HIV prevention and treatment. Household food insecurity affects hundreds of millions of individuals in Sub-Saharan Africa, a region that experiences a disproportionate burden of the HIV pandemic. Both maternal HIV diagnosis and household food insecurity may be linked with maternal stress. This in turn may lead to unhealthy coping behaviors. We examined the independent associations of HIV, persistent household food insecurity and the synergistic effect of both on maternal stress.

Mothers of infants (n = 328) born between 1996 and 1999 in four Guatemalan communities were interviewed every 2 wk until 6 mo postpartum (pp) to collect prospective breast-feeding data and assess the association between delayed (>3 d pp) onset of lactation (OL) and the risk of ending full breast-feeding. Cox proportional hazards regression was used to examine the association between delayed OL and the hazard of ending full breast-feeding in the first 6 mo, adjusted for potential confounders and effect modifiers. A significant interaction with community was found (community-specific hazard ratios: HR_A = 2.87, 95% CI = 1.25, 6.60; HR_B = 3.43, 95% CI = 1.55, 7.59; HR_C = 0.26, 95% CI = 0.06, 1.14; HR_D = 1.11, 95% CI = 0.44, 2.77). Supplementation before OL (preonset supplementation) was associated with delayed OL [odds ratio (OR) = 4.87, 95% CI = 2.29, 10.36] and an increased risk of ending full breast-feeding (HR = 1.49, 95% CI = 1.05, 2.11). In the two communities in which mothers who experienced delayed OL had a significantly greater risk of ending full breast-feeding than did mothers experiencing normal OL, the association between delayed OL and full breast-feeding was mediated in part by preonset supplementation. Further analyses suggest that this was due to delayed OL leading to nonbreast milk feeds, rather than to introduction of supplements delaying OL. We conclude that some mothers who experience delayed OL are less likely to continue full breast-feeding in the first 6 mo and that further research should examine the contextual factors that modify this relationship.