What this Trial Is About

Background: At least 30% of Americans have fatty liver disease. This means that they store too much fat in the liver. At the moment lifestyle changes are the only way to treat this problem. Objective: To test how (1) a low-carbohydrate diet and (2) a supplement called nicotinamide riboside (NR) affect how a person s body uses dietary fat. Eligibility: Men aged 18 to 65 and women aged 18 to 50 who are healthy volunteers with a body mass index (height to weight ratio) of 25 or more. Adults with maturity-onset diabetes of the young type 2 (MODY2) are also needed. Design: Participants with diabetes will have 1 screening visit and a 9-day clinic stay. Healthy volunteers will have 1 screening visit and 2 clinic stays of 1 to 2 weeks each. During screening, all participants will have a physical exam with blood and urine tests. They will have their heart rhythm measured while riding a gym bike. NR is a pill taken by mouth. Only healthy volunteers will take the NR, for 14 days at a time, during 1 clinic stay. During their other stay, they will take placebos; these are pills that look like the study supplement but contain no NR. During each clinic stay, all participants will eat a normal American diet. Then they will eat a ketogenic "low-carb" diet for 5 days. Participants will have many tests, including: Sleeping every night and having two 24-hour stays in a special room that measures the gases their body uses and produces. Drinking a high-fat shake, then remaining seated for 5 hours while their blood and breath are monitored. Having a substance injected into the arm and remaining seated for 3 hours while their blood is measured. Wearing monitors to measure their activity levels. Another monitor will measure their blood glucose levels. Having imaging scans. ...

Effect of Nicotinamide Riboside on Ketosis, Fat Oxidation & Metabolic Rate