This is an investigator initiated study being conducted in equal numbers at two sites, University of California, San Diego (UC San Diego) and Emory University (EU). The purpose of this study is to understand the potential of a low sugar diet for the treatment of nonalcoholic fatty liver disease (NAFLD) in children. Forty boys with NAFLD will be randomly assigned to either an intervention group or a habitual diet control group. The intervention will be a low sugar diet for a period of 8 weeks. The effect of this dietary change will be assessed using advanced magnetic resonance imaging (MRI) testing to measure liver fat.

Inclusion Criteria:

• Boys age 11-16 years inclusive.
• Clinical history consistent with NAFLD.
• Biopsy-proven NAFLD
• MRI measured Liver Proton Density Fat Fraction ≥10%
• alanine aminotransferase (ALT) ≥ 45 u/L
• No evidence of any other liver disease by clinical history or histological evaluation.
• Written informed consent from parent or legal guardian.
• Written informed assent from the child or adolescent.

Exclusion Criteria:

Exclusions will not be based upon gender, race, or ethnicity. Participants with a current history of the following conditions or any other health issues that make it unsafe for them to participate in the opinion of the Investigators will be excluded from the study:

• History of significant alcohol intake (Alcohol Use Disorders Identification Test [AUDIT]) or inability to quantify alcohol consumption
• Chronic use (more than 2 consecutive weeks) of medications known to cause hepatic steatosis or steatohepatitis in the past year.
• The use of other known hepatotoxins within 120 days of baseline
• History of total parenteral nutrition (TPN) use in the year prior to screening
• History of bariatric surgery or planning to undergo bariatric surgery during the study duration
• Significant depression
• Non-compensated liver disease with any one of the following hematologic, biochemical, and serological criteria on entry into protocol:
• Hemoglobin < 10 g/dL
• White blood cell < 3,500 cells/mm
• Neutrophil count < 1,500 cells/mm3 of blood
• Platelets < 130,000 cells/mm3 of blood
• Direct bilirubin > 1.0 mg/dL
• Total bilirubin > 3 mg/dL
• Albumin < 3.2 g/dL
• International normalized ratio (INR) > 1.4
• Evidence of other chronic liver disease
• Children who are currently enrolled in a clinical trial or who received an investigational study drug or a medication with the intent to treat NAFLD/NASH in the past 60 days
• Contraindications to MRI, e.g. metal in the eyes, implanted electronic devices, aneurysm clips, pacemaker, cochlear implants
• Unable to have or complete the MRI exam due to body weight exceeding scanner table limit or girth exceeding scanner bore diameter
• Subjects who are not able or willing to comply with the protocol or have any other condition that would impede compliance or hinder completion of the study, in the opinion of the investigator
• Families with > 5 individuals
• Failure to give informed consent

De-identified participant data will be made available in response to bona fide and good faith, ad hoc requests. Suitability of each request, if consistent with Institutional Review Board (IRB) approval, will be determined only in the case of a favorable vote of a majority of a committee consisting of each consortium investigator and the Grantor. Data will be made available with a signed access agreement.

The baseline analysis population includes all participants who consented to participate in the study and met eligibility criteria

Adverse event details were collected throughout the duration of study participation, from the Baseline visit through the Week 8 follow up visit.

For this study, an adverse event is considered any untoward medical occurrence in a subject participating in a clinical study that does not necessarily have a causal relationship with the dietary intervention.