Ketogenic Diet for Core Symptoms in Children with Autism Spectrum Disorder: A Randomized Controlled Trial

Abstract

Background: Evidence for ketogenic dietary therapy in autism spectrum disorder (ASD) remains limited, particularly from randomized pediatric trials.

Objective: To evaluate the efficacy and short-term safety of a ketogenic diet (KD) for improving core ASD symptoms in children.

Methods: In this single-center randomized controlled trial, 34 children aged 3–10 years with ASD were randomized 1:1 to a KD or individualized balanced diet for 3 months. The KD was gradually titrated from a 1:1 to a 3:1 fat-to-(carbohydrate + protein) ratio. The primary outcome was change in the Gilliam Autism Rating Scale, Third Edition (GARS-3), assessed by a blinded psychologist. Anthropometry, ketosis, and adverse events were also monitored.

Results: GARS-3 scores decreased from 100.76±11.49 to 89.12±11.54 with KD, compared with an increase from 100.35±16.47 to 102.88±13.70 in controls. Percentage change was −11.44±7.10% versus +3.41±9.51% (P<0.001). Severity-category improvement occurred in 41.2% versus 5.9% (P=0.039). Weight decreased by 2.90% versus increased by 1.51% (P<0.001). No significant difference in height change was observed. All KD participants achieved urinary ketosis, with no clinically significant adverse events.

Conclusion: A supervised 3-month KD improved ASD symptom severity and was well tolerated. Larger, longer-term trials are warranted.

Trial registration: Retrospectively registered with Open Science Framework (OSF): https://osf.io/6qhu9/; DOI: 10.17605/OSF.IO/6QHU9.