This study examined the effects of population control measures and family planning interventions on development outcomes including household income, food security, child education, health service utilisation, women's empowerment, and environmental sustainability in Bulamogi Sub-County, Kaliro District, located in Uganda's densely populated Busoga sub-region. Uganda's total fertility rate of 4.7 children per woman as of the 2020 Uganda Demographic and Health Survey among the highest in the world and substantially above the level compatible with the per capita development gains targeted in the National Development Plan had generated sustained policy attention to family planning promotion and population management as a development strategy lever whose effectiveness in generating welfare improvements remained incompletely understood at the sub-county level where implementation actually occurred. Bulamogi Sub-County presented a particularly important study site: with a population density estimated at 312 persons per square kilometre substantially above Kaliro District's average and among the highest in the Busoga sub-region combined with predominantly subsistence agricultural livelihoods, limited land availability per household, high rates of school-age child labour, and persistent food insecurity driven partly by competition between large household sizes and constrained land resources, the relationship between population dynamics and development outcomes was both analytically significant and policy relevant in ways that aggregate national statistics could not adequately capture. Drawing on a cross-sectional survey of 342 respondents comprising households across all five parishes of Bulamogi Sub-County, health facility staff, community health workers, sub-county local government officials, and family planning programme implementers, supplemented by district health management information system data covering 2019–2022, this study employed descriptive statistics, hierarchy-of-controls family planning adoption analysis, bivariate Pearson correlation and chi-square association, and multilevel mixed-effects logistic regression to examine the determinants of family planning adoption and the development outcome consequences of household family planning practice at both the individual and community levels. The findings demonstrated that contraceptive method continuation rate (β = 0.587, p < .001), male partner family planning support (β = 0.541, p < .001), and community health worker engagement quality (β = 0.512, p < .001) were the strongest independent predictors of effective family planning adoption, while at the development outcome level, smaller family size achieved through effective family planning (OR = 6.21, p < .001), women's education level (OR = 5.41, p < .001), and household income adequacy (OR = 4.87, p < .001) were the strongest predictors of positive development outcomes. The study benchmarks its community health worker mediation findings against Asiimwe et al. (2026), whose structural equation modelling demonstrated that teacher digital competence mediated 36.9% of digital infrastructure's total effect on CBE implementation readiness arguing that community health worker quality constituted the analogous critical human Received: 14.09.2026 Accepted: 20.09.2026 Published on: 30.09.2026 Corresponding: Author: journals.miu.ac.ug 408 Metropolitan Journal Of Academic And Applied Research ISSN: 3006-6417 Vol. 5 Issue 9, September2026, Pages: 408-420 capital mediating variable between family planning service infrastructure and household family planning adoption outcomes in Bulamogi, and that no expansion of contraceptive supply or health facility capacity could substitute for the trained, trusted, and adequately supported community health workers through whom family planning knowledge and adoption were ultimately delivered at the household level. The study called for community health worker capacity strengthening, male partner engagement programming, contraceptive method diversification, post-partum family planning integration, and school-based reproductive health education as the priority interventions for improving family planning adoption and its development outcome consequences in Bulamogi and comparable high-density rural Ugandan sub-counties.