 Approximately 100 patients will be randomized in this study, 20 to each of of the three MBX-2982 treatment groups, 20 to placebo, and 20 to the sitagliptin group. Patients will be taking 3 tablets and 1 capsule daily. This sample size provides the minimum number expected to ensure a power of at least 80 to detect a 20 decrease in the weighted mean glucose level associated with an extended mixed meal tolerance test with 2 standardized meals relative to placebo after 4 weeks of daily treatment with MBX-2982, assuming a drop-out rate of 20 and a common SD of 25. 