Plant-derived polyphenols (e.g., epigallocatechin-3-gallate (EGCG), resveratrol), alkaloids (e.g., berberine), and marine carotenoids (e.g., fucoxanthin) demonstrate remarkable capacity to modulate fundamental obesity pathways through (A) suppression of adipogenesis via PPARγ and C/EBPα inhibition, (B) activation of lipolysis through hormone-sensitive lipase (HSL) stimulation and AMPK phosphorylation, (C) enhancement of thermogenesis via UCP1 upregulation, and (D) gut microbiome modulation through SCFA production. The gene discussed is UCP1; the disease is obesity due to melanocortin 4 receptor deficiency.