BACKGROUND: The prevalence of metabolic syndrome (MetS) has increased significantly in sub-Saharan African countries, including Uganda. Females are disproportionately affected by MetS compared to males. This study evaluated the effects of 12 weeks of community-based nutrition education (NE), physical activity (PA), and motivational interviewing (MI) interventions on MetS and its components among females of reproductive age in central Uganda. METHODS: We conducted a randomised parallel-group trial involving 120 females aged 15-49 years with MetS in Wakiso district, central Uganda. Participants were recruited between April and May 2023 and were randomly assigned to either the intervention (n = 60) or the control (n = 60) group. The 12-week intervention included NE, PA, and MI. The outcomes included changes in MetS and its components. Data were collected at baseline and endline using a modified STEPS questionnaire to assess sociodemographic factors, blood pressure (BP), waist circumference (WC), fasting blood glucose (FBG), triglycerides, HDL cholesterol (HDLC), and other variables. A generalised linear model was used to evaluate the impact of time and study groups on metabolic outcomes. Analyses were conducted using intention-to-treat in Stata (SE/14.0), at a p-value of <
0.05. RESULTS: The group x time interaction showed significant positive effects on MetS and its components at the endline. The intervention group had significantly lower odds of MetS compared to the control group [OR = 0.588, 95% CI (0.501, 0.690), p-value <
0.0001)]. The intervention showed reduced mean diastolic BP (coeff=-4.556, 95% CI (-9.035, -0.077), p-value = 0.046), reduced mean FBG (coeff=-1.012, 95% CI (-1.553, -0.470), p <
0.001), and increased mean HDLC (coeff = 0.139, 95% CI (0.015, 0.262), p-value = 0.028). Additionally, the intervention group had significantly higher odds of daily fruit and vegetable intake compared to the control group (OR = 6.31, 95% CI: 1.18-33.64,p = 0.031), increased moderate-intensity recreational activity (Coeff = + 155.65 min/week, 95% CI:19.11-292.22, p = 0.025) and reduced sedentary time by 43.94 min per day (Coeff= -43.94, 95% CI: -87.75 to- 0.13, p = 0.049). CONCLUSIONS: The community-based interventions significantly improved MetS outcomes among females of reproductive age in Uganda. Scaling up this package of interventions should be explored. TRIAL REGISTRATION: ISRCTN, ISRCTN17445597. Registered 06 June 2024 - Retrospectively registered, https://www.isrctn.com/ISRCTN17445597 .