Metabolic Effects of Betaine Supplementation

Inclusion Criteria: * 1\) Men and women aged 21-65 years old; * 2\) Dysglycemia/prediabetes is defined as impaired fasting glucose (≥100 mg/dl), impaired glucose tolerance (2 hour post 75 g oral glucose load 140-200 mg/dl) or HbA1c 5.7-6.5%); * 3\) overweight to grade 3 obesity (BMI 25 to 45 kg/m2). Exclusion Criteria: * 1\) cystathionine beta-synthase (CBS deficiency); * 2\) Presence of liver disease other than NAFLD; * 3\) Use of medications causing steatosis; * 4\) Known alcohol consumption ≥ 2 drink per day; * 5\) Use of medications known to cause insulin resistance; * 6\) Use of weight loss drugs (or program) within 3 months of screening; * 7\) Treatment with any experimental drug within the past 6 months; * 8\) Subjects must be willing to abstain from use of phosphodiesterase type 5 (PDE-5) inhibitors; * 9\) Pregnancy or lactation, and women of child bearing potential must use adequate contraception; * 10\) Surgery within 30 days of screening; * 11\) Heart disease defined as New York Heart Association Class III or IV cardiac status or hospitalization for congestive heart failure, unstable angina, myocardial infarction, cerebrovascular accident, transient ischemic attack or any revascularization within 6 months; * 12\) Uncontrolled hypertension; * 13\) eGFR \<60; 14) History of acquired immune deficiency syndrome; * 15\) History of malignancy within 5 years; * 16\) Hemoglobin \<12 g/dL (males), \<10 g/dL (females); * 17\) Triglycerides (TG) \>500 mg/dL; * 18\) Poor mental function or any other reason to expect patient difficulty in complying with study requirements; * 19\) Metal clips or implants that preclude magnetic resonance imaging.