<<A number of studies have previously shown that young children did better
in school when they ate sweetened breakfast cereals and that adults also
scored better when consuming glucose compared with placebo>>


The problem with extrapolating these studies with the statement "sugar makes
you smarter" is the placebo (i.e., no food).  A better comparison meal might
be meat or fish with some seasonal fruits and veggies.

The second problem might be measuring how long after eating a sweetened
breakfast cereal cognitive performance measurements were taken.  Were they
taken soon after, when blood sugar was on the rise?  Or were they taken
three to four hours afterwards, when excess insulin has had a chance of
lowering blood sugar levels and cognitive performance might be expected to
decline?

<<But if the liver can catabolise excess protein to make glucose in its
dietary absence, why would there be such a difference?>>

A more common physiological mechanism would be glucagon from the pancreas
triggering the liver to convert its glycogen stores to blood glucose.  This
process normally helps fasting glucose levels remain around the 87 mg/dl
range.

But I guess that the brain does a bit better at slightly higher blood sugar
levels (note, however, that the original study did not link blood sugar
levels with cognitive performance).  But these slightly higher levels could
have been achieved in a more wholesome way with meat/fish and some "good"
carbs (seasonal fruits/veggies).

Normally, the Nutrition News Focus does a good job at pointing out
limitations to extrapolation of the findings of studies.  But this
interpretation reveals the Nutrition News bias towards a high carb diet IMO.

Rob