Complementary Feeding Practices and Nutritional Status Among Pakistani Children Aged 6–23 Months: A Pooled Analysis of Nationally Representative Surveys

Background: Milk feeding practices are a critical determinant of nutritional status in infancy, yet the relationship between specific milk feeding combinations and undernutrition remains poorly characterized in Pakistan, where animal milk use is widespread and the malnutrition burden is among the highest in South Asia. Methods: We pooled data on 96,736 children aged 6–23 months with valid anthropometry from 13 nationally and provincially representative cross-sectional surveys (2010–2020). Analyses were restricted to Punjab, Sindh, Khyber Pakhtunkhwa and Balochistan. Seven mutually exclusive feeding combinations were defined from 24 h dietary recall. Survey-weighted, age-stratified logistic regression (6–11 and 12–23 months) examined associations with stunting and wasting, adjusting progressively for area, household and child-level factors, with breastfeeding plus complementary feeding as the reference. Micronutrient deficiency data from NNS 2011 and NNS 2018 were analyzed descriptively. Results: Among infants aged 6–11 months, non-human milk (NHM) alone—predominantly unfortified buffalo or cow milk—was independently associated with elevated odds of stunting (OR: 1.54, 95% CI: 1.20–1.96) and wasting (OR: 1.86, 95% CI: 1.42–2.45) in fully adjusted models. Among children aged 12–23 months, NHM with complementary foods (NHM+CF) was independently protective against both stunting (OR: 0.73, 95% CI: 0.66–0.80) and wasting (OR: 0.80, 95% CI: 0.72–0.89). Household poverty was the strongest determinant of undernutrition in every stratum. Anemia (59.1%), ferritin deficiency (50.4%), iron deficiency anemia (33.0%) and vitamin D deficiency (63.1%) remained highly prevalent in 2018, and were highest in children receiving milk without complementary foods. In contrast, multiple micronutrient deficiency was elevated across most NHM-containing feeding groups regardless of complementary food status; after adjustment, NHM+CF and BM+NHM remained independently associated with multiple micronutrient deficiency at 12–23 months (OR: 1.35, 95% CI: 1.04–1.77 and OR: 1.52, 95% CI: 1.05–2.20, respectively). Conclusions: The nutritional correlates of NHM use are strongly age-dependent: adverse in the first year when it substitutes for breast milk without complementary foods, and favorable after 12 months as part of a diversified diet. Feeding interventions should be embedded within poverty-reduction frameworks. All data were cross-sectional, so these associations are not causal.