Calorie Restriction: Prescription for a Long Life or a Short One?

The idea that restricting your calories will lengthen your life is an increasingly popular one--unless of course you are among the one billion people who go to bed hungry every night and can look forward to a shortened life expectancy as a consequence. The research on caloric restriction is taking place in the richer countries with high life expectancy, and so ignores the fact that for most of human history people were struggling to increase their caloric intake. Indeed, the evidence suggests that improved diets (more calories) helped Europeans to lead the way to lower mortality because better nutrition increases the body's chances of fending off disease. However, the nutrition transition, first put forward by Barry Popkin of UNC Chapel Hill, suggest that as societies modernize, their diet and exercise patterns change and we become prone to obesity as a result of, among other things, excessive caloric intake:

Citizens of the world's richest countries are getting fatter and fatter and the United States is leading the charge, an organization of leading economies said Thursday in its first ever obesity forecast.

Three out of four Americans will be overweight or obese by 2020, and disease rates and health care spending will balloon, unless governments, individuals and industry cooperate on a comprehensive strategy to combat the epidemic, the study by the Organization for Economic Cooperation and Development said.

The Paris-based organization, which brings together 33 of the world's leading economies, is better known for forecasting deficit and employment levels than for measuring waistlines. But the economic cost of excess weight — in health care, and in lives cut short and resources wasted — is a growing concern for many governments.

In my view, this is where the value of caloric restriction comes in. Rather than concerning ourselves with a few months of extra life that might be possible with severe caloric restriction (and never mind the potentially diminished quality of life that might accompany that lifestyle), we should be more concerned with everyday limitation of calories and with everyday exercise as a way of trying to keep evolution and modernization in balance.