If we watch how much we eat, the promise has been that we can extend lifespan. That notion has now been put to the test.

FOX News Radio's Bill Vitka reports:

Stay hungry, live longer. Decades of experiments have shown that limiting calories extends longevity by 30% to 40%, at least, in lab animals.

If that worked on people, less on the dinner plate would mean more years of life. But it doesn't. It turns out skinny monkeys don't live any longer than those at more normal weight. Life expectancy, no greater according to the study in the journal Nature.

Limiting calories appears to provide some benefits. It may lower the risk of heart disease. But in men it means low testosterone and problems with bone density.

Bill Vitka, FOX News Radio