Amino acids may change how the body controls blood sugar

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria - Obese Subjects with Type 2 Diabetes: * HbA1c ≤ 8.5% (type 2 diabetic subjects). * HbA1c ≤ 6.5% (obese and lean subjects). * BMI ≥ 28 Kg/M\^2 (Obese subjects with and without type 2 diabetes). * BMI ≤ 25 Kg/M\^2 (Lean subjects without type 2 diabetes). * Use of sulfonylureas or metformin only (type 2 diabetec subjects). * For female subjects: negative pregnancy test at the time of enrollment or study. * No history of prior upper abdominal surgery such as adjustable gastric banding, pyloroplasty and vagotomy. * No active systemic illness or malignancy. * No symptomatic macrovascular or microvascular disease. * No contraindications to MRI (e.g., metal implants, claustrophobia). * Hematocrit \> 35%. * TSH \> 0.4 or \< 5.5. * Consumption of \< 2 alcohol drinks per day or \< 14 per week or a negative AUDIT questionnaire. Exclusion Criteria - Obese Subjects with Type 2 Diabetes: * HbA1c ³ 8.5% * BMI ≤ 28 Kg/M2 * Use of insulin or agents other than sulfonylureas or metformin. * For female subjects: positive pregnancy test at the time of enrollment or study * History of prior upper abdominal surgery such as adjustable gastric banding, pyloroplasty and vagotomy. * Active systemic illness or malignancy. * Symptomatic macrovascular or microvascular disease. * Contraindications to MRI (e.g., metal implants, claustrophobia). * Hematocrit \< 35% * TSH \< 0.4 or \> 5.5. * Consumption of \> 2 alcohol drinks per day or \> 14 per week or a positive AUDIT questionnaire. Inclusion Criteria - Obese Subjects without Type 2 Diabetes: * BMI ≥ 28 Kg/M2. * \> 5% liver fat content, as determined by MRI using the proton density fat fraction (PDFF) technique. Exclusion Criteria - Obese Subjects without Type 2 Diabetes: * HbA1c ≥ 6.5% * BMI ≤ 28 Kg/M2 * Use of any glucose-lowering agents including metformin or sulfonylureas. * For female subjects: positive pregnancy test at the time of enrollment or study * History of prior upper abdominal surgery such as adjustable gastric banding, pyloroplasty and vagotomy. * Active systemic illness or malignancy. * Symptomatic macrovascular or microvascular disease. * Contraindications to MRI (e.g., metal implants, claustrophobia). * Hematocrit \< 35% * TSH \< 0.4 or \> 5.5. * Consumption of \> 2 alcohol drinks per day or \> 14 per week or a positive AUDIT questionnaire. Inclusion Criteria - Lean subjects without Diabetes: \- BMI ≤ 25 Kg/M\^2). Exclusion Criteria - Lean Subjects without Diabetes: * HbA1c ≥ 6.5%. * BMI ≥ 25 Kg/M\^2. * Use of any glucose-lowering agents including metformin or sulfonylureas. * For female subjects: positive pregnancy test at the time of enrollment or study. * History of prior upper abdominal surgery such as adjustable gastric banding, pyloroplasty and vagotomy. * Active systemic illness or malignancy. * Symptomatic macrovascular or microvascular disease. * Contraindications to MRI (e.g., metal implants, claustrophobia). * Hematocrit \< 35%. * TSH \< 0.4 or \> 5.5. * Consumption of \> 2 alcohol drinks per day or \> 14 per week or a positive AUDIT questionnaire. * Liver fat content ≥ 5% as determined by MRI using the proton density fat fraction (PDFF) technique.