Oct 01, · A substantial proportion of patients with adult-onset diabetes share features of both type 1 diabetes (T1D) and type 2 diabetes (T2D). These individuals, at diagnosis, clinically resemble T2D patients by not requiring insulin treatment, yet they have immunogenetic markers associated with T1D. Such a slowly evolving form of autoimmune diabetes, described as latent autoimmune diabetes of adults Cited by: 3. A proper diet is also an effective way to treat adult onset diabetes. Meals should be eaten around the same time of day and consist of roughly the same proportion of protein to starches. Spinach, beans, barley, tomatoes, fat free dairy products, oatmeal, and citrus fruits .