The prevalence of type 2 diabetes mellitus (T2DM) has risen exponentially, and the number of incidences increases every day. The purpose of this article is to summarize the experimental evidence supporting the important association between nutrition and diet-based therapy for the control and management of T2DM. Evidence from several in vitro, in vivo, and human studies broadly found that nutrition-based therapy enriched with several important phytochemical constituents modulates lipid and carbohydrate metabolism, and it ameliorates glucolipotoxicity and insulin resistance. Besides these activities, nutrition-based therapy has also been shown to improve adipose tissue metabolism and to alleviate various proinflammatory processes, oxidative stress, and stress-sensitive signaling pathways. Dietary recommendations for patients with type 2 diabetes emphasize diet-based therapy and include excellent sources of dietary fibers and polyphenols.