Here is an interesting article documenting the cellular effects of primates on CR(Caloric Restriction) for 4 years. It appears they have more insulin sensitivity. But this was not due to the increased production of the receptors or a decrease in processing.
In summary, if you want to live longer and have more insulin sensitivity....Eat Less.
Read further here....
Diabetes July 2009 58:1488-1498; published ahead of print March 31, 2009,