Plain language summary
The prevalence of non-alcoholic fatty liver disease (NAFLD) among children in the United States is increasing and evidence supports a role for dietary sugar in the development and progression of NAFLD. This open-label, randomised clinical trial using a feeding study design was performed to test the hypothesis that restricting free sugar would improve NAFLD in children. Children in the intervention group, who were provided all food for the 8 week intervention, received less than 3% of daily calories from sugar. The control group continued with their usual diet. Study visits were conducted at baseline and at 4 and 8 weeks after start of the intervention. The mean decrease in hepatic steatosis (a sign of NAFLD) from baseline to week 8 was significantly greater for the intervention diet group compared with the usual diet group. Liver enzymes, total cholesterol, weight/body mass index and systolic blood pressure also improved more in the low sugar group than in the usual diet group. There was no difference in markers for blood sugar control and other lipid parameters. The authors conclude that these findings suggest a potential benefit of a low sugar diet for children with NAFLD, but state that further research is needed to assess long-term and clinical outcomes.
Abstract
Importance: Pediatric guidelines for the management of nonalcoholic fatty liver disease (NAFLD) recommend a healthy diet as treatment. Reduction of sugary foods and beverages is a plausible but unproven treatment. Objective: To determine the effects of a diet low in free sugars (those sugars added to foods and beverages and occurring naturally in fruit juices) in adolescent boys with NAFLD. Design, Setting, and Participants: An open-label, 8-week randomized clinical trial of adolescent boys aged 11 to 16 years with histologically diagnosed NAFLD and evidence of active disease (hepatic steatosis >10% and alanine aminotransferase level ≥45 U/L) randomized 1:1 to an intervention diet group or usual diet group at 2 US academic clinical research centers from August 2015 to July 2017; final date of follow-up was September 2017. Interventions: The intervention diet consisted of individualized menu planning and provision of study meals for the entire household to restrict free sugar intake to less than 3% of daily calories for 8 weeks. Twice-weekly telephone calls assessed diet adherence. Usual diet participants consumed their regular diet. Main Outcomes and Measures: The primary outcome was change in hepatic steatosis estimated by magnetic resonance imaging proton density fat fraction measurement between baseline and 8 weeks. The minimal clinically important difference was assumed to be 4%. There were 12 secondary outcomes, including change in alanine aminotransferase level and diet adherence. Results: Forty adolescent boys were randomly assigned to either the intervention diet group or the usual diet group (20 per group; mean [SD] age, 13.0 [1.9] years; most were Hispanic [95%]) and all completed the trial. The mean decrease in hepatic steatosis from baseline to week 8 was significantly greater for the intervention diet group (25% to 17%) vs the usual diet group (21% to 20%) and the adjusted week 8 mean difference was -6.23% (95% CI, -9.45% to -3.02%; P < .001). Of the 12 prespecified secondary outcomes, 7 were null and 5 were statistically significant including alanine aminotransferase level and diet adherence. The geometric mean decrease in alanine aminotransferase level from baseline to 8 weeks was significantly greater for the intervention diet group (103 U/L to 61 U/L) vs the usual diet group (82 U/L to 75 U/L) and the adjusted ratio of the geometric means at week 8 was 0.65 U/L (95% CI, 0.53 to 0.81 U/L; P < .001). Adherence to the diet was high in the intervention diet group (18 of 20 reported intake of <3% of calories from free sugar during the intervention). There were no adverse events related to participation in the study. Conclusions and Relevance: In this study of adolescent boys with NAFLD, 8 weeks of provision of a diet low in free sugar content compared with usual diet resulted in significant improvement in hepatic steatosis. However, these findings should be considered preliminary and further research is required to assess long-term and clinical outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT02513121.
Methodological quality
Jadad score
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2
Allocation concealment
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Not applicable
