I am becoming increasingly convinced that ketone bodies play an important role in ADHD. Ketone bodies are an alternative fuel source for the brain that becomes critically important when glucose levels in the blood are low . As has been said before, the brain is unable to utilize fatty acids as fuel. However, it can utilize ketone bodies, and thus their presence becomes a protective mechanism for the brain when glucose is in short supply.
Ketone bodies are produced by the liver as a by-product of fat metabolism. In the absence of fats in the diet, significantly fewer ketone bodies are produced; i.e., the body derives more ketone bodies from dietary fat than from internally synthesized fats . Furthermore, and most significantly, certain specialized cells in the brain called astrocytes are also able to scavenge free fatty acids from the blood and manufacture ketone bodies from them. It is hypothesized that ketone bodies in the brain can also act as "cellular substrates, thereby preserving neuronal synaptic function and structural stability." (, abstract). I suspect that astrocytes may be able to accumulate stores of ketone bodies that can serve both as fuel for the brain in times of glucose deficiency, and to assure that important signals such as dopamine get transmitted across synaptic junctions. But insufficient dietary fats will significantly reduce the availability of this critical nutritional resource.