How does reduced calorie intake increase life span?

Michael - There's been some very compelling evidence in invertebrates, in flies and in nematode worms that reduced calorie intake is somehow boosting the cell's ability to withstand all kinds of stress. So, the shortage of nutrients for those cells is a stress in itself. By switching on the resistance to that, it also switches on resistance to many other kinds of stress as well. So that's the best that we understand at the moment that it seems to be some kind of general upregulation of ability to withstand stress.

Ben - And I think it's probably important to point out that when we're talking about calorie restriction, we're not talking about not having that extra doughnut or having a slightly smaller bowl of cereal in the morning. These calorie restriction experiments are really quite extreme, aren't they?

Michael - Yes, they are quite severe. I do know that there are some human studies going on to test this, but I certainly wouldn't like to be a subject in those experiments.