Objective: To examine the contribution of selected child-, maternal-and householdrelated factors to child undernutrition across two different age groups of Kenyan under-5s. Design: Demographic and Health Survey data, multistage stratified cluster sampling methodology. Setting: Rural and urban areas of Kenya. Subjects: A total of 1851 children between the ages of 0 and 24 months and 1942 children between the ages of 25 and 59 months in Kenya. Results: Thirty per cent of the younger children were stunted, 13 % were underweight and 8 % were wasted. Forty per cent of the older children were stunted, 17 % were underweight and 4 % were wasted. Longer breast-feeding duration, small birth size, childhood diarrhoea and/or cough, poor maternal nutritional status and urban residence were associated with higher odds of at least one form of undernutrition, while female gender, large birth size, up-to-date immunization, higher maternal age at first birth, BMI and education level at the time of the survey and higher household wealth were each associated with lower odds of at least one form of undernutrition among Kenyan children. The more proximal child factors had the strongest impact on the younger group of children while the intermediate and more distal maternal and household factors had the strongest impact on child undernutrition among the older group of children. Conclusions: The present analysis identifies determinants of undernutrition among two age groups of Kenyan pre-school children and demonstrates that the contribution of child, maternal and household factors on children's nutritional status varies with children's age.

High levels of food insecurity and human immunodeficiency virus (HIV) infection place most breastfeeding mothers in Kenya at high risk of malnutrition. We examined the role of selected socio-economic, demographic and health factors as determinants of nutritional status among HIV-infected and HIV-uninfected mothers in rural Kenya and further examined the interrelationship between maternal nutritional and child nutritional status within this population. A cross-sectional design was used to collect data from non-pregnant mothers with children ages 4-24 months in Kisumu District, Kenya. Over 80% of the mothers were breastfeeding at the time of the study. Mean maternal body mass index (BMI) (21.60 ± 3.15) and percent body fat (22.29 ± 4.86) values were lower than among lactating mothers in other Sub-Sahara African countries. Maternal HIV status was not significantly associated with any of the maternal nutritional indicators assessed in the study. Breastfeeding, recent severe illness and having multiple children below 2 years of age were negatively associated with maternal nutritional status, while higher maternal age, socio-economic status and household food security were each positively associated with maternal nutritional status. Significant positive association was reported between maternal weight, height, BMI, mid-upper arm circumference (MUAC), body fat and fat-free mass estimates, and children's height-for-age, weight-for-age, weight-for-height and MUAC-for-age z-score. This analysis identifies determinants of maternal nutritional status in rural Kenya and highlights the importance of interventions that address malnutrition in both HIV-infected and HIV-uninfected mothers in rural Kenya. Significant association between maternal and child nutritional status stresses the importance of addressing maternal and young child nutritional status as interrelated factors.