Exenatide, a GLP-1 agonist approved for lowering blood glucose concentrations in patients with type 2 diabetes, has been associated with restoration of the first-phase insulin response when administered intravenously to patients with type 2 diabetes. In longer clinical trials, it is associated with progressive decreases in body weight, and improvement in the dyslipidemia that characterizes insulin resistance, although insulin resistance was not quantified. The investigators will seek to determine whether exenatide would have similar effects in individuals who were not diabetic. in particular, the drug effect on beta cell function and insulin sensitivity would be subject to less confounding by changes in blood glucose in the prediabetic population, allowing for clearer evaluation of the physiological effects of the drug on these metabolic endpoints. The investigators will compare 2 groups of prediabetic insulin resistant individuals, all on a weight loss diet and one group on exenatide and the other on placebo. The investigators will evaluate restoration of first phase insulin response, potential glucose lowering effects, including both reversal of prediabetes and hypoglycemia, and improvement in insulin resistance.

Inclusion Criteria:

• Healthy Men and women, BMI 27-37kgm2, Fasting plasma glucose = or > 100 mg/dL and = or < 99 125m g/dl or a 2 hour post OGTT = > 140 mg/dl or = or < 199 mg/dl

Exclusion Criteria:

• Diabetes, Active cardiac, kidney, liver, pulmonary, or other major organ diseases are cause for exclusion. Other exclusionary criteria include: use of corticosteroids, diet medications, antipsychotic medications, history of eating disorder, history of bariatric surgery, active malignancy, recent weight change of more than 2%, inability to attend follow-up visits, excessive alcohol use, investigator's discretion that it is not in patient's best interest