To evaluate the impact of a Low Carbohydrate Ketogenic Diet (LCKD) weight loss program and compare to the standard of care program established for patients with Non-Alcoholic Fatty Liver Disease (NAFLD) on: (1) Liver fat and liver stiffness scores, (2) lipid profile and insulin sensitivity; and (3) depression scores and quality of life, and (4) Cardiometabolic measures such as cardiopulmonary exercise test (CPET) and transthoracic echocardiogram (TTE).

This prospective pilot pragmatic trial will investigate the role of a LCKD weight loss program for obese patients (BMI ≥30 kg/m2) and compare it to the group of known obese NAFLD patients who receive dietetic counseling as part of their standard of care in a dedicated NAFLD program. All participants (n=50) will be recruited at Virginia Commonwealth University (VCU).

Patients will do initial paperwork including

Questionnaires QOL, eating disorder screen, depression screen:

QOL, eating disorder screen and depression screen.

Labwork:

Data will be collected from routine care labwork to include a fasting cholesterol panel, insulin, A1c and comprehensive panel (if they have not received these labs in the preceding 3 months), and at 6 and 12 months. A1c will be collected at 3,6,9 months as well (if A1c >/=7), or just additionally at 6 months if A1c <7

Study labs will be collected:

Blood at 0, 3, 6 and 12 months Urine, stool and saliva at 0, 1, 3 and 12 months

Fibroscan will be done at 0, 3, 6 and 12 months

Echo/CPET testing and Room calorimetry will be offered and the patients agreeing to do this will have them done at 0, 3 and 12 months

Inclusion Criteria:

• The inclusion criteria include patients aged 18 years and older, BMI ≥ 30, ALT (alanine transferase) > 19 (female) and > 30 (male) or radiographic evidence of hepatic parenchymal disease and seen in either the PIs weight loss clinic or a patient in the VCU NAFLD (non-alcoholic fatty liver disease) program.

Exclusion Criteria:

• Patients will be excluded if they have known other liver disease such as viral hepatitis, autoimmune hepatitis, liver transplant, severely ill, weekly alcohol use (>14 drinks in men and >7 drinks in women), HIV, pregnant females, those< 18 years, and prisoners.

50 people from the PI's weight loss clinic using an a priori ketogenic diet. Will be compared with 50 people from a NAFLD clinic using a low calorie, low fat diet.