Eating a low-calorie diet probably won't help extend our lives.
At first glance, that observation following a recent study involving a group of 121 monkeys doesn't seem very reassuring to those of us who try to restrict our food intake and maintain a trim physique. But a long life is not necessarily a healthy life and, in that regard, the study contained more reassuring news.
Researchers at the National Institutes of Health's animal center in Maryland tracked a colony of rhesus monkeys for more than 20 years and found that the animals that had caloric intake restricted to 30 percent less had the same lifespan as monkeys with unrestricted eating.
That conclusion did not match the results of similar comparisons conducted among rats and mice, which were found to live 15 percent to 40 percent longer if they ate 30 percent to 40 percent less than their counterparts. Unfortunately for humans, we are a lot more like monkeys than mice.
The better news from the monkey study was that the low-cal primates had lower rates of diabetes and stark differences in cancer rates. No dieting monkey was diagnosed with cancer, compared with six cases of cancer in the control group. Some of the calorie-restricted monkeys also had lower cholesterol, triglycerides and glucose levels -- and they looked younger.
The lesson for humans is that, if living well is the goal, eating a low-calorie diet is a healthy way to achieve it.