The present invention provides compositions and methods for treating and/or preventing diseases and disorders associated with expression of PPAR .gamma. and/or infiltration of macrophages into skeletal muscle tissue and/or white adipose tissue. The method treats such diseases and disorders with abscisic acid (ABA). Exemplary diseases and disorders include diabetes, including type 2 diabetes, prediabetes, glucose intolerance insulin resistance, and diseases and disorders involving the immune system, such as inflammation, including obesity-related inflammation, inflammatory bowel disease, type 1 diabetes, multiple sclerosis, allergies, asthma, cardiovascular disease, and arthritis.