The demand for novel three-dimensional (3D) cell culture models of adipose tissue has been increasing, and proteomic investigations are important for determining the underlying causes of obesity, type II diabetes, and metabolic disorders. In this study, we performed global quantitative proteomic profiling of three 3D-cultured 3T3-L1 cells (preadipocytes, adipocytes and co-cultured adipocytes with macrophages) and their 2D-cultured counterparts using 2D-nanoLC-ESI-MS/MS with iTRAQ labelling. A total of 2,885 shared proteins from six types of adipose cells were identified and quantified in four replicates. Using iTRAQ-based quantitative assessments, we found that the primary proteins involved in carbohydrate and fatty acid metabolism, adipogenesis and the electron transport chain were highly expressed in 3D cell culture system when compared to those of 2D-cultured cells. Furthermore, it was also shown that the expression levels of proteins associated with metabolic pathways, carbon metabolism and glycolysis/gluconeogenesis were up-regulated, whereas proteins implicated in both DNA replication and the cell cycle were expressed at lower levels compared to those of the 2D mono-cultured cells. Based on these results, the 3D adipocyte model can help elucidate the mechanisms underpinning metabolic syndromes and aid the development of new medical treatments for metabolic disorders.