Key subgroup findings included: (1) Obese older adults and those with MetS experienced 2–3 times greater WC reduction than healthy peers; (2) Vigorous physical activity (VPA) was more effective than moderate-to-vigorous physical activity (MVPA) in lowering TNF-α; (3) Short-term interventions (<6 months) prioritized inflammation reduction (TNF-α, IL-6), while long-term interventions (≥6 months) better improved BMI. This evidence concerns the gene IL6 and metabolic syndrome.