It has been known for some time now that underfed rats and mice live much longer. Recent research on humans is too premature to determine that reduction of calorie intake is enough to extend life. It may take a long time to prove humans can actually live longer by eating less.
However, based from what is known from research, those people who have chosen to calorie restrict their diet have experience tremendous health benefits, including lower risk of heart disease, stroke and diabetes, which accelerate with aging.
Ongoing research will establish whether people can carefully regulate calorie intake and eating habits to extend life.