caloric-restriction diet

"Andrzej Bartke and colleagues at Southern Illinois University in
Springfield worked with normal mice and mutant mice missing the
receptor for growth hormone. Half of each type were allowed to eat at
will, and the other half were fed 30 per cent fewer calories than
usual. As expected, normal mice on fewer calories lived 20 to 30 per
cent longer. Mice without the growth hormone receptor also showed
similar increases in longevity on a normal diet.

This suggests that restricting calories has a similar effect on the
body to knocking out the growth hormone receptor. Doing both does not
make the mice live even longer: the mutant mice on low-calorie diets
had similar lifespans to those on the normal diet (Proceedings of the National Academy of Sciences, vol 103, p 7901).

"The actions of growth hormone are somehow implicated in linking
caloric restriction to longer life," Bartke says. Insulin may be the
connection. Both groups of long-lived mice had a greater sensitivity to
insulin, and caloric restriction in the mutant mice failed to increase
their strong insulin sensitivity any further.

"Insulin
resistance is a risk factor for just about any problem you don't want
to get: diabetes, atherosclerosis, cancer. It's sort of intuitive that
the opposite situation would be beneficial."

"

New Scientist