Urban slum children in Kenya often face nutritional deficiencies due to limited access to balanced meals and educational resources. A mixed-methods approach combining quantitative data from dietary surveys and qualitative insights through focus group discussions among parents and teachers. School lunch programmes significantly improved nutrient intake by an average of 20% (95% CI: 10-30%) in participating children, with a notable increase in vitamin A consumption. The school lunch programmes are effective in enhancing nutrition among urban slum children, warranting further expansion and refinement to achieve optimal health outcomes. Continue monitoring the nutritional impact over time and consider incorporating more diverse food options to cater to varied dietary needs. School Lunch Programmes, Urban Slums, Nutrition Improvement, Kenyan Children The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.