This study aimed to investigate the effect of fermented vegetable juice (VJ) obtained from a blend of four crops (Brassica oleracea var. capitata, B. oleracea var. italica, Daucus carota L., and Beta vulgaris) on adipogenesis along with the identification of active compounds. Two lactic acid bacteria (LAB) (Companilactobacillus allii WiKim39 and Lactococcus lactis WiKim0124), isolated from kimchi, were used to ferment the VJ and their effectiveness was evaluated in differentiated human mesenchymal stem cells and obese mice. In vitro antibody array analysis was done to understand signaling proteins in adipogenesis. Gene Ontology enrichment analysis showed that differentially expressed proteins are related to biological processes including immunological processes. These were effectively regulated by LAB and fermented VJ. Supplementation of fermented VJ reduced the weight gain, blood biochemical indicators, and liver fat accumulation in mice. Oil Red O staining indicated that the fermentation metabolites of VJ (indole-3-lactic acid, leucic acid, and phenyllactic acid) had an inhibitory effect on lipid accumulation in vitro. Therefore, it can be concluded that LAB-fermented VJ and its metabolites have the potential to counter obesity, and thus can be therapeutically effective.