Abstract: Type 2 diabetes mellitus arising from obesity is one of the most serious noncommunicable diseases which currently have serious impacts on human health. Chronic inflammation in adipose tissue is the key to developing type 2 diabetes mellitus in obese people. This paper firstly reviews the progress in the relationship between obesity mediated by inflammation and type 2 diabetes mellitus from the cellular and molecular levels, focusing on immune cells and signaling pathways. Secondly, it summarizes the results of dietary intervention in targeting immunocytes and signaling pathways, which can adjust the polarization of macrophages, the function of T cells and the activities of various signaling pathways in order to seek the special medical purposes with safe, healthy and efficient lowering blood glucose, so as to provide ideas and programs for the dietary intervention of type 2 diabetes mellitus.