I'm a physician. There are a lot of problems with the original article.<p>The body is excellent at maintaining glucose concentration in the blood with food or with days of fasting. Glucose is the primary short-term energy source for most cells. The brain's energy requirements vary very little with "thinking" despite the assertions to the contrary in the introduction of this article. PET works by noting the slight transient increases in some brain regions with active thought, but moments later (as that 20% of blood flow goes swishing through the brain) more glucose is available. Meanwhile you are digesting sugars and carbohydrates, and your liver is supplying most of your fresh glucose if you are a fasting adult.<p>Already, before reading the article, I have a low pre-test probability of their hypothesis being true, so they need extraordinarily strong evidence to make their point. Instead, there is a very weak chain of experiments, poorly reported, with borderline statistical significance. Poor charts, no tabulated results, just terrible.<p>The primary problem is that they assert that glucose fluctuations occur due to the exercise of willpower. They try and fail to show this with their first experiment. However, their "results and discussion" combined section shows that their control group before and after glucose were very close to their post-intervention group glucose. p327 para 1.<p>This shows how weak their statistics and data are, and from this point, you can throw the whole study in the trash.