Effects of the ketogenic diet on nutritional status, resting energy expenditure, and substrate oxidation in patients with medically refractory epilepsy: A 6-month prospective observational study

This 6-month prospective, single-arm observational study was designed to assess the effects of the KD on the nutritional status, resting energy expenditure (REE), and substrate oxidation in patients with drug-resistant epilepsy. Eighteen patients with medically refractory epilepsy underwent assessment of body composition, REE, and substrate oxidation rates before and after 6 months of KD. Compared with baseline, there were no statistically significant differences at 6 months in terms of height, weight, BMI z-scores, and REE. However, the respiratory quotient decreased significantly (from 0.800.06 to 0.720.05, p<0.001) whereas fat oxidationwas significantly increased (from50.925.2 mg/ min to 97.525.7 mg/min, p<0.001). Interestingly,we found that the increase in fat oxidationwas the main independent predictor of the reduction in seizure frequency (beta¼0.97, t¼6.3, p < 0.05). Administering a KD for 6 months in patients with medically refractory epilepsy increases fat oxidation and decreases the respiratory quotient, without appreciable changes in REE.