For decades, people have restricted their calories purely to lose weight and fit into their favorite clothes. Health often hasn't factored into the equation. Now, a growing subset of health-conscious folks is advocating calorie restriction as a way to tap the fountain of youth. In other words, eat less and you'll ward off a host of diseases and live longer. But is it true? Can you extend your lifespan simply by pushing away your dinner plate after one or two servings of nutritious food?
Science says maybe you can. Studies on mice, fish, flies and worms indicate that reducing the calories they ingest enables them to live longer and lower their chances of contracting diseases. Studies on monkeys are less conclusive, but they appear to show a lower death rate and lower levels of age-related illnesses in monkeys who were fed fewer calories. Calorie restriction seems to reduce metabolic rate and the stress on the body caused by oxidation. It also bolsters insulin function and makes the nervous system function more efficiently.
This does not mean, of course, that calorie restriction is a definitive panacea for aging in humans. But studies and personal anecdotes suggest that it holds promise for people looking to live as long and as well as possible. In one study, 28 members of the Calorie Restriction Society, a group that espouses calorie restriction as a lifestyle, had their thyroid hormones measured against a control group. The results showed that calorie restrictors had more desirable hormone levels than the control group, even though the control group was also exercising.
It's important to note that calorie restrictors are not starving themselves or dropping their calories to unhealthful levels. Many of them eat up to 1,800 calories a day. The difference between calorie restrictors and conventional dieters is that restrictors tend to focus on eating the most nutritious foods possible to fill themselves up: lots of produce, lean protein, and whole grains. It's common to hear from calorie restrictors that they rarely get sick, have lots of energy and generally feel better than ever. This makes sense, since obesity is a known risk factor for a slew of diseases and conditions, and doctors have been telling us that even being a few pounds overweight can be bad for us. We all can probably take a cue from calorie restrictors and start cutting back (even a little) on the amount of food we eat so we can experience better health and longer, more satisfying lives!
Sources: Fontana L, Klein S, Holloszy J.O., Premachandra B N., Effect of Long-Term Calorie Restriction with Adequate Protein and Micronutrients on Thyroid Hormones, Journal of Clinical Endocrinology & Metabolism, 91 (8), 3232-3235; Colman R.J., Anderson R.M., Johnson S.C., Kastman E. K., Kosmatka K.J., Beasley T.M., et. al, Caloric Restriction Delays Disease Onset and Mortality in Rhesus Monkeys, Science, (10) July 2009, 201-204; Heilbronn L.K., Ravussin E, Calorie Restriction and Aging: Review of the Literature and Implications for Studies in Humans, American Journal of Clinical Nutrition, 78 (3), 361-369; Calorie Restriction Society, www.crsociety.org.
