Cutting calories may help keep you slim, but it won’t add years to your life, according to a new study published in the journal Nature. Researchers from the National Institute of Aging tracked a group of rhesus monkeys on a calorie-restricted diet for 24 years to study the relationship between a low-calorie diet and aging. The result: Calorie restriction, also referred to as The Longevity Diet, did not lengthen these primates lives.
Scientists have been studying this relationship since the 1930s, when one study found that mice lived up to 40 percent longer when fed a restricted diet. Many studies since then have found similar results. "Once they found that calorie restriction did increase the lifespan in rodents, it was important to investigate it in a primate species," says Mark Beasley, Ph.D., associate professor of biostatistics at the University of Alabama-Birmingham and one of the researchers on the study. But unfortunately for groups like the Calorie Restriction Society, the results did not follow suit in this particular study.
Calorie restriction advocates insist that just by decreasing your caloric intake roughly 10 to 30 percent, you can add years to your life. But it's really less about the quantity of years and more about improving the quality of life, says Julie Mattison, Ph.D. of the U.S. National Institute on Aging, who led the scientists in the NIA study.
For example, researchers are hoping that future studies may reveal if restricting calories can help prevent age-related diseases. Mattison cited that none of the primates who were put on a calorie-restricted diet at a younger age had cancer. Scientists also found improvements in other health measures, including lower fasting glucose levels, lower cholesterol levels, and lower triglycerides levels, which all help decrease risk for heart disease and prevent diabetes.
“Longevity is one thing, but even more important, I think, is how your health impacts your quality of life. The best things you can do, in my opinion, to maintain optimum health and a high quality of life is to incorporate physical activity into your daily life and maintain a healthy body weight,” says James O. Hill, Ph.D., director at the Center for Human Nutrition and director of Colorado Nutrition Obesity Research Center (NORC).
What This Means For You
While calorie restriction may not extend your life, the NIA findings can definitely help shed light on how to improve health in the long run.
Hill says he is not a fan of caloric restriction, highlighting probably the most important aspect: It’s just not fun. Instead, he recommends concentrating on the quality of your diet, choosing lean proteins, unprocessed carbohydrates, and healthy fats, and letting yourself enjoy some treats once in a while. "You can do this if you are active," he says, adding that you should try for at least an hour of some kind of exercise daily. Last, don't gain weight. And if you need to lose a few pounds, Hill also revealed his patients' most successful tool for weight loss: getting a pedometer and starting to walk.