It has previously been shown that an increase in the consumption of fiber improves glucose control in type 2 diabetes. In addition, previous pilot studies have shown that a diet solely based on oat flakes can improve insulin sensitivity and glucose control in poorly controlled type 2 diabetes. Recent clinical data indicates, that early hyperglycemia can be normalized by a diet high in fiber. In this controlled pilot study, a food containing liquid oat bran high in fiber will be studied in type 2 diabetes patients with inadequate glucose control that are treated with oral medication or with additional once-daily insulin only against a reference product. 30 patients will be treated with the oat bran product or reference product over a period of 6 weeks in a double blinded approach, hereafter all participants will be switched to the oat bran product. The primary endpoint will be fasting glucose after 6 weeks. Secondary endpoints will be long-term glucose control as measured by HbA1c, self-documented glucose as well as the body weight and body mass index.