The irony of industry fortification: Aligning industry-led fortified dairy-based food products with population nutritional needs in Côte d’Ivoire and Nigeria

Sub-Saharan Africa faces a triple burden of malnutrition, the coexistence of undernutrition, micronutrient deficiencies, and overweight or obesity, within rapidly urbanising populations. Market-driven food fortification, whereby manufacturers voluntarily add micronutrients to commercial products, has been proposed as a complementary strategy to address micronutrient deficiencies in low- and middle-income countries. However, its public health value depends critically on alignment with population-specific nutritional needs. This thesis developed and applied a structured framework to evaluate the feasibility and effectiveness of industry-led fortification of dairy-based food products for school-aged children and women of reproductive age in Côte d'Ivoire and Nigeria, in collaboration with FrieslandCampina. The thesis was organised around three research themes. The first characterised population nutritional needs in urban Côte d'Ivoire through a cross-sectional dietary intake survey (n = 884). Calcium, riboflavin, and zinc were the most prevalent inadequacies among both school-aged children and women of reproductive age, while iron intake was adequate for the majority. Most women (>50%) were overweight or obese, consistent with early-stage nutrition transition. Dietary patterns were city-specific, with fish-, vegetable-, and dairy-based patterns associated with higher diet quality and lower non-communicable disease risk. A methodological comparison demonstrated that the nutriR modelling tool produced inadequacy estimates comparable to traditional methods when high-quality usual intake data were available, though it does not reduce the need for rigorous primary dietary assessment. The second theme assessed the technological and commercial feasibility of improving iron bioavailability in fortified flavoured dairy powder products by substituting ferric pyrophosphate with more bioavailable iron compounds. Bench-scale trials found that encapsulated ferric pyrophosphate was the only substitute with acceptable sensory and technological properties, but its cost was five times higher than the reference, rendering reformulation economically infeasible. Ferrous fumarate was identified as a viable alternative in non-flavoured or cereal-based formats, and a commercially available multi-nutrient fortified milk-based maize porridge containing this compound was selected for evaluation in Nigeria. The third theme evaluated the effectiveness of this porridge, delivered through a School Feeding Programme, in a randomised, double-blind controlled trial in Ibadan, Nigeria (n = 945). Despite high baseline anaemia prevalence (74%), the intervention did not improve haemoglobin concentrations or iron status. Inflammation-adjusted iron deficiency affected only 9.5% of participants, and body iron stores were adequate in 99.8%, indicating that anaemia in this population was predominantly driven by inflammation, vitamin A deficiency, and malaria rather than iron-responsive deficiency. Modest improvements were observed in vitamin D status in the high-dose group, and vitamin A status improved across all groups. Together, these findings underscore a central irony of industry-led fortification: a nutrient-dense, carefully reformulated product may produce limited public health impact when the underlying aetiology of the target condition has not been thoroughly characterised. Effective market-driven fortification requires diagnostic-driven product design, grounded in high-quality population data, before evaluation.