Harvard Stem Cell Institute Executive Committee member Amy Wagers, PhD, and her lab team at Harvard University have conducted studies on stem cells and their ability to maintain function as a person gets older.  In terms of increasing lifespan, "that in a large number of organisms, reduced calorie intake — in the absence of malnutrition — has been shown to extend life span, particularly healthy lifespan," decreasing calorie intake, increases longevity of a person, as long as you don't take it too far. 

In their studies on mice, the ones with the reduced calorie diets (12 weeks of 40% reduction) responded quicker, faster, and better to muscle damage.  Going off of this, the team tested ability of stem cell transplantation.  The ones from CR (Caloric Restriction) diet mice created twice as many muscle fibers as non-CR diet stem cells. To conclude, Wagers' study's data supports the idea that consuming less calories increases longevity, muscle rebuilding ability fro m stem cells, and reduces diabetes, cancer, and other common chronic diseases and conditions.  (http://hsci.harvard.edu/caloric-restric … generation)

Hello, my name is Tina from China. After reading your article, it let me feel I am reading a news. You should add more your thinking knowledge and experiment.
Talking about food and hunger, I am very surprised that you tell "decreasing calorie intake, increases longevity of a person, as long as you don't take it too far." But I am not make sense to "as long as you don't take it too far." From this sentence, I know people eat less can be healthier than eat more food. And now growing obesity is a important issue. I still remember on departure from Dubai back to China, a very fat man was sitting tourist class，I afraid to he will broke his seat.

Is obesity a problem in China?

I didn't realize that a change in diet by only 40% can change so much in people's lives. Coming from America, obesity is a major issue that needs to be solved.