: Physical activity and Mediterranean diet adherence are important components of lifestyle management in patients with metabolic syndrome (MetS) and alcohol-related liver disease (ALD). We evaluated 12-month changes in lifestyle, metabolic parameters, and non-invasive fibrosis-related markers and explored their associations. : In this 12-month prospective observational study, 50 adults with MetS and ALD were assessed at baseline, 6 months, and 12 months. Physical activity (IPAQ-SF), Mediterranean diet adherence (MEDAS-14), alcohol consumption status, liver stiffness, FIB-4, and APRI were evaluated. Exploratory multivariable analyses adjusted for sustained alcohol abstinence, baseline liver disease severity, age, sex, and change in waist circumference. : Physical activity increased from 455.2 ± 154.1 to 910.3 ± 275.4 MET-min/week and MEDAS-14 from 4.32 ± 0.62 to 7.92 ± 0.92 (both < 0.001). Waist circumference, fasting glucose, LDL cholesterol, and triglycerides decreased significantly (all < 0.001). At 12 months, physical activity and Mediterranean diet adherence were inversely correlated with liver stiffness, FIB-4, and APRI (all ≤ 0.010). However, changes in IPAQ-SF and MEDAS-14 were not significantly associated with changes in non-invasive fibrosis-related markers after multivariable adjustment. Sustained alcohol abstinence (74.0%) was consistently associated with more favorable changes in all three markers. : Improvements in physical activity and Mediterranean diet adherence occurred alongside favorable metabolic and liver-related changes, but their associations with non-invasive fibrosis-related markers were not maintained after adjustment for major potential confounders. Sustained alcohol abstinence was consistently associated with more favorable changes in these markers.