This review summarises the recent findings on metabolic treatments for epilepsy and Amyotrophic Lateral Sclerosis (ALS) in honour of Professor Ursula Sonnewald. The metabolic impairments in rodent models of these disorders as well as affected patients are being discussed. In both epilepsy and ALS, there are defects in glucose uptake and reduced tricarboxylic acid (TCA) cycling, at least in part due to reduced amounts of C4 TCA cycle intermediates. In addition there are impairments in glycolysis in ALS. A reduction in glucose uptake can be addressed by providing the brain with alternative fuels, such as ketones or medium-chain triglycerides. As anaplerotic fuels, such as the triglyceride of heptanoate, triheptanoin, refill the TCA cycle C4/C5 intermediate pool that is deficient, they are ideal to boost TCA cycling and thus the oxidative metabolism of all fuels.