BACKGROUND: In research settings, plant-based (vegan) eating plans improve diabetes management, typically reducing weight, glycemia, and low-density lipoprotein (LDL) cholesterol concentrations to a greater extent than has been shown with portion-controlled eating plans.

Methionine-restricted diets (MRD) show an integrated series of beneficial health effects, including improving insulin sensitivity, limiting fat deposition, and decreasing oxidative stress, and inflammation responses. We aimed to explore the systemic responses to a MRD in mice fed with a high fat (HFD) and clarify the possible mechanism. Mice were fed with a control diet (0.86% methionine + 4% fat, CON), HFD (0.86% methionine + 20% fat), or MRD (0.17% methionine + 20% fat) for 22 consecutive weeks. HFD-fed mice showed widespread systemic metabolic disorders and thyroid dysfunction.

Type 1 diabetes is considered to be an autoimmune disease in which T lymphocytes infiltrate the islets of pancreas and destroy the insulin producing beta cell population. Besides antigen specificity, the quality of immune reactivity against islet cell antigen(s) is an important determinant of the beta cell destruction. Much evidence indicates that the function of the gut immune system is central in the pathogenesis, as the regulation of the gut immune system may be aberrant in type 1 diabetes.

Several studies have suggested that dietary protein quality may be an important determinant in the natural history of renal disease. We have therefore studied the effects of a predominantly vegetarian diet in eight patients with Type 1 diabetes mellitus and an albumin excretion rate (AER) in excess of 30 micrograms min-1. The AER was measured after an 8-week run-in period on the patient's usual diet, and again after 8 weeks of a predominantly vegetarian diet in which the proportion of vegetable protein was supplemented in order to minimize the reduction in total dietary protein intake.