I'm sure that the study accurately reflects their findings. However, anyone
who has given even a cursory read to the relevant literature on ketogenic
diets is aware that there is a transition period during which cognitive
function may be mildly compromised. This is because the brain uses either
glucose or ketone bodies for energy. Since ketone bodies are a byproduct of
metabolizing fat for entergy, it takes time to make the shift. Depending on
a number of factors it can take anywhere from 2-3 days to 2-3 weeks to make
the transition to producing and burning ketone bodies. Had the study allowed
a reasonable "wash out" period for subjects to move from one state to the
other, which is commonly done in well designed studies, the cognitive
advantage might well have been on the side of those in ketosis.
This could have been a landmark study. It is most disappointing that their
design was so sloppy.
Best Wishes,
Ron Hoggan