Ketogenic therapy is a treatment for intractable epilepsy involving a high fat, adequate protein, and low carbohydrate diet. A prospective study was conducted to examine serum beta‐hydroxybutyrate (BHB) and glucose (Glu) response at fasting, 30 min, 1 hr, and 2 hr after the ingestion of a ketogenic meal. Patients were stratified by age and route of feeding and comparisons were made for BHB/Glu and percent change from fasting. Data were available for 23 patients with mean age of 10.2±5 years and time on diet of 51.4±38 months. Mean percent changes at 30 min, 1 hr, and 2 hr for both BHB and Glu were less than 10%. Regression analyses were performed for BHB/Glu and percent changes and ratio, Cal/kg/day, fat, carbohydrate, and protein % of calories, fat and carbohydrate in g/kg/day and all correlations (r) were found to be less than 0.5 and r2 less than 0.3. Time on diet correlated to percent change of BHB at 30 min (r=0.5, r2=0.3, p=0.01). Fasting BHB/Glu was negatively correlated with age (r= ‐0.5, r2=0.2, p=0.03). Overall, BHB and Glu levels are maintained relatively constant. Stabilization of energy metabolism may be a factor in the mechanism of action against seizures.Effect of time after meal and age on BHB/Glu*p<0.05, #p=0.09 comparing <10yr and >10yrGrant Funding SourceNIH ‐ General Clinical Research Center