(OR27-04-24) Effects of a Ketogenic Diet on Anthropometric and Biochemical Parameters of Adolescents With Obesity and Nonalcoholic Fatty Liver Disease: A Randomized Controlled Trial

Objectives: This study aims to assess the effects of a four-month ketogenic diet program (KDP, 5-10% carbohydrates, 70% fat, 20-25% protein) on adolescents with obesity and nonalcoholic fatty liver disease (NAFLD), compared to a standard lifestyle modification program (LMP, 45-65% carbohydrates, 20-35% fat, 10-35% protein).

Methods: Chinese adolescents aged 14-18 years with obesity and NAFLD diagnosed by magnetic resonance imaging were randomly assigned to either KDP (n=28) or LMP (n=27). Both had weekly dietary counseling with dietitians. At baseline and after four months, anthropometric and biochemical (liver function test, glycemic traits and lipid profile) parameters were measured. Intention-to-treat analyses were conducted using paired t-test for within-group comparison and independent t-test for between-group comparison of continuous variables (Registration number: ChiCTR2100050042).

Results: After the primary four-months’ intervention, both arms reduced their body mass index, waist circumference and body fat percentage by bioimpedance analysis compared to baseline (p < 0.001 for KDP; p = 0.04, 0.03 and 0.03, respectively, for LMP), while those on KDP achieved a greater reduction (p < 0.01). Decreased levels of alanine aminotransferase (ALT) (p < 0.001), aspartate aminotransferase (AST) (p < 0.001), AST/ALT ratio (p = 0.002), fasting insulin (p < 0.001), homeostasis model assessment-estimated insulin resistance (p < 0.001), quantitative insulin-sensitivity check index (p < 0.001) and triglycerides (p < 0.001) were observed in the KDP arm, but not in the LMP arm, except for decreased AST levels (p = 0.03). Low-density lipoprotein cholesterol concentration did not significantly change in both arms, while there was a small reduction in total cholesterol (p = 0.02) and high-density lipoprotein (p < 0.001) concentration in the LMP arm. There were no drop-outs throughout the intervention.

Conclusions: A four-month ketogenic diet reduced obesity-related parameters and improved biochemical markers of liver function and glucose homeostasis in adolescents with NAFLD. The results provided evidence that, in these adolescents, a ketogenic diet may be as effective or more effective than a standard LMP diet.

Funding Sources: This project is funded by Health and Medical Research Fund, Food and Health Bureau, Hong Kong Special Administrative Region Government.