Just found this little ditty -- imagine it was the high cab diet that
interfeed with the brain's use of glucose!!

Effects of unbalanced diets on cerebral glucose metabolism in the adult rat.
 al-Mudallal AS, Levin BE, Lust WD, Harik SI. Department of Neurology, Case
Western Reserve University School of Medicine, Cleveland, OH, USA.
Neurology 1995 Dec;45(12):2261-2265
 We measured regional cerebral metabolic rates for glucose and selected
cerebral metabolites in rats fed one of the following diets for 6 to 7 weeks:
(1) regular laboratory chow; (2) high-fat, carbohydrate-free ketogenic diet
deriving 10% of its caloric value from proteins and 90% from fat; and (3)
high-carbohydrate diet deriving 10% of its caloric value from proteins, 78%
from carbohydrates, and 12% from fat. In preliminary experiments, we found
that moderate ketosis could not be achieved by diets deriving less than about
90% of their caloric value from fat. Rats maintained on the ketogenic diet
had moderately elevated blood beta-hydroxybutyrate (O.4 mM) and acetoacetate
(0.2 mM), and a five- to 10-fold increase in their cerebral
beta-hydroxybutyrate level. Cerebral levels of glucose, glycogen, lactate,
and citrate were similar in all groups. 2-Deoxyglucose studies showed that
the ketogenic diet did not significantly alter regional brain glucose
utilization. However, rats maintained on the high-carbohydrate diet had a
marked decrease in their brain glucose utilization and increased cerebral
concentrations of glucose 6-phosphate. These findings indicate that long-term
moderate ketonemia does not significantly alter brain glucose
phosphorylation. However, even marginal protein dietary deficiency, when
coupled with a carbohydrate-rich diet, depresses cerebral glucose utilization
to a degree often seen in metabolic encephalopathies. Our results support the
clinical contention that protein dietary deficiency coupled with increased
carbohydrate intake can lead to CNS dysfunction.
Namaste, Liz