Still, there's plenty of evidence from those animal studies to suggest that restricting calories—either by a consistently reduced food intake, skipping meals, or fasting—might be good for humans, too, says Mark Mattson, a neuroscientist at the National Institute on Aging who was also an author of the asthma study. He says there are at least two possible mechanisms. Eating less cuts down on the production of free radicals, which damage cells and can lead to disease. He also says that there's a cellular response similar to what happens when we exercise. Like working out, going without calories is mildly stressful to the cells at the time, but beneficial over the long run. "Dietary restriction is about the best dietary advice I can give you," says Levitsky. "We don't know about living a longer life, but all the markers are in a favorable direction."
You may have noticed, though, that the bottom line to any of these meal skipping or reducing techniques is cutting down on the overall number of calories you eat and thus losing weight. That is never easy, but for some people, skipping a meal or two a week or taking a day every month away from food, or eating a lot less during a given meal or on every other day may be more appealing than simply cutting calories all the time.