It's been shown in mice, fish, and yeast; now the first study of long-term calorie restriction in humans suggests that if you really want to live longer, eat less.
Few people are willing to cut back drastically on their caloric intake for years on end. But researchers at Washington University in St. Louis managed to locate 18 (15 of them men), aged 25 to 82, who have spent an average of 6 years following nutritionally balanced diets recommended by the Calorie Restriction Society. The scientists compared them with 18 people, otherwise clean livers, on a "typical Western diet." On average, the subjects ate 1700 calories a day, compared with at least 2100 for the controls, says lead investigator Luigi Fontana, who also works for the Italian institute of health.
Dr. Atkins notwithstanding, the subjects lost a lot of weight while consuming 46% of their calories as complex carbohydrates. Their "bad" cholesterol, blood lipids, and diabetes risk markers went way down. Blood pressures dropped to childhood levels. The subjects' bodies were 9% fat--compared with 24% for controls and, surprisingly, with 12% for people who run 50 miles a week, says Fontana. And none of the dieters had plaque on their carotid arteries, the scientists report online 19 April in the Proceedings of the National Academy of Sciences.
William Harlan, a nutrition expert and clinical trials adviser to the National Institute of Mental Health, calls the study "provocative." He points out that even though the study subjects were self-selected, "the differences that are present are striking. ... More studies like this [would] provide us a better idea of what a truly healthful diet would look like."