Heat processed ginseng, Sun ginseng (SG), has been reported to have improved therapeutic properties compared to raw forms, such as increased efficiencies of anti-diabetic, anti-inflammatory, and anti-hyperglycemic effects. The aim of the present study was to investigate the anti-obesity effects of SG through the suppression of cell differentiation and proliferation of mouse 3T3-L1 preadipocyte cells and the lipid accumulation in Caenorhabditis elegans (C. elegans).