Patient description: The patient is a 34-year-old obese woman who comes to the clinic with weight concerns. She is 165 cm tall, and her weight is 113 kg (BMI: 41.5). In the past, she unsuccessfully used antiobesity agents and appetite suppressants. She is complaining of sleep apnea, PCO and dissatisfaction with her body shape. She is a high-school teacher. She is married for 5 years. She doesn't use any contraceptive methods for the past 4 months and she had no prior pregnancies. She rarely exercises and movement seems to be hard for her. She is not able to complete the four-square step test in less than 15 seconds. She does not smoke or use any drugs. Her BP: 130/80, HR: 195/min and her BMI is: 41.54. Her lab results: FBS: 98 mg/dl TG: 150 mg/dl Cholesterol: 180 mg/dl LDL: 90 mg/dl HDL: 35 mg/dl She is considering a laparoscopic gastric bypass.

Clinical trial eligibility criteria: eligible ages (years): 18.0-45.0,  Glucose Metabolism Disorder Male or female aged 18 2. Weight stable for at least 3 months prior to screening (< 5% weight change) 3. BMI of 21 4. Cohort 1 Aspartame Consumers: Primary dietary sweetener is aspartame; consumes at least 36 ounces of diet soda in which aspartame is a primary ingredient (Diet Coke or Diet Dr Pepper) a day for at least 6 months duration prior to study enrollment (Primary dietary sweetener is aspartame" should be defined as: "840g per week sucrose equivalent from aspartame and less than 280 grams per week sucrose equivalent from all other sweeteners (non-caloric and caloric sweeteners). For reference, one 12oz soda is 40g sucrose equivalent, and one teaspoon (one packet) of artificial sweetener is 4g sucrose equivalent.)" Cohort 2 Aspartame Naïve Participants: Consumes less than or equal to 2 cans of diet soda per week 5. Screening Visit #2 OGTT Outcome h plasma glucose < 110 mg/dl AND h plasma glucose < 140 mg/dl 6. Abnormal OGTT during the screening phase of the study (area under curve on the high end of distribution) 7. Must be able to comply with a metabolic Prudent diet 8. Willing to fast 10 hours before each OGTT and BodPod 9. Current level of exercise (aerobic and/or resistance training) must be able to be sustained while an in-patient  Any evidence of US National Cholesterol Education Program Adult Treatment Panel III Clinical Identification of the Metabolic Syndrome (must have 3 or more of the following risk factors): Abdominal Obesity, given as a waist circumference Men >102 cm (>40 in) Women > 88 cm (>35 in) Triglycerides >150 mg/dl HDL Cholesterol Men < 40 mg/dl Women <50 mg/dl Blood Pressure >130/ >85 mm Hg Fasting Glucose > 110 mg/dl 2. Average systolic blood pressure (SBP) > 150 mmHg and / or diastolic blood pressure (DBP) > 90 mmHG (based on 3 BPs taken at screening visit #1), 3. LDL-C > 240mg/dl 4. Triglycerides > 400 mg/dl 5. Evidence of a liver disorder (ALT > three fold of the ULN) 6. Evidence of any renal disease 7. Currently on a weight-loss diet 8. Diabetes 9. Self-reported history of thyroid dysfunction 10. Sugar sweetened beverage consumption (> 84 ounces per week) 11. Hemoglobin <13.0 g/dl for males and 12.0 g/dl for females 12. Current, prior (within 2 months), or anticipated use of any of the following medications: antihyperlipidemic, hyperglycemic medications, Antineoplastics, Antiretrovirals, Selective Serotonin Reuptake Inhibitors, Diuretics, Antihypertensives, Anticonvulsants, Hormone therapy, Birth control 13. Self-reported antibiotic use within the previous 3 months 14. Currently pregnant or lactating 15. History of cardiac disease 16. Active illegal drug user (self-reported) 17. History of GI surgery (gastric bypass, bariatric, Roux-en-Y, colon resection, etc.) 18. Habitual ingestion of > 2 alcoholic beverages/day 19. Ever diagnosed with an eating disorder (self-reported) 20. Use of steroids or beta agonists (orally, intranasal or inhaled) within a week of any OGTT 21. Positive Hepatitis Serology (Hep. B surface Antibody; Hep. B surface antigen; Hep. C surface antibody) 22. HIV Positive 23. Tobacco use within the past 3 months 24. Any medical or social condition that, in the opinion of the Investigator, might pose additional risk to the participant or confound the results of the study