A Modest -- and Slimming! -- Proposal
America is fat and getting fatter. Today 140 million American adults are overweight or obese. Their bodies carry 4 billion pounds of excess fat, the result of eating 14 trillion excess calories.
Numbers of this size belong in the domain of economists, not physicians. And therein lies the solution.
Medical and public health attempts to control obesity should continue, but it is time to add marketplace approaches. The first step is realizing that, nationally, weight gain is not a medical problem, it's a pollution problem.
Food calories are so pervasively and inexpensively available in our environment that they should be regarded as a pollutant. Just as an asthmatic can't help but inhale pollutants in the air all around him, we Americans cannot help but ingest the calories present in the environment all around us. Our Stone Age biology is optimized to survive famine by triggering eating at the slightest provocation. We are not optimized to eat prudently in an environment of cheap and easy calories.
Public policies have succeeded in reducing air pollution. They can teach us how to reduce calorie pollution. Tradable emission allowances, for example, establish markets where permits to emit air pollutants can be bought and sold. Market forces then provide incentives to reduce pollution emissions.
A program for tradable emission allowances could target foods with a high caloric density, that is, foods with a high number of calories per ounce. These foods are more likely to produce weight gain than foods with a low density of calories. It's easier to eat 1,000 calories in dessert than in vegetables, because the calories in dessert are concentrated.
A food's caloric density generally depends on its water and fat content. Dry, fatty foods have the highest caloric density, because water has weight but no calories and because fat has more calories per ounce than proteins and carbohydrates. For example, butter, which is fatty and dry, has 195 calories per ounce. Frozen spinach has seven calories per ounce.
A specific example illustrates how tradable emission allowances could work. Suppose the calorie-emission allowance is set to 100 calories for each ounce of food emitted into the environment (i.e., sold). A four-ounce food item having more than 400 calories could not, therefore, be sold unless "calorie credits" were purchased to cover the excess calories. So a standard four-ounce stick of butter, containing 780 calories, could not enter the marketplace until the butter producer acquired 380 additional calorie-credits from someone having credits to sell.
On the other hand, the producer of a four-ounce block of frozen spinach would emit only 28 calories into the environment and could sell the unused 372 calorie-credits to the butter producer.
With such a program, high-density foods would become more expensive and low-density foods would become cheaper. Unlike a tax, the program could be designed so the net cost change to consumers was zero. Thus, consumers who alter their eating habits need pay no more to eat the same number of calories. The hope, which should be tested, is that the number of calories eaten would drop, owing to the difficulty of consuming large numbers of calories from low-density foods. This would then reduce food costs and, ultimately, health-care costs.
To avoid shocking the marketplace, the calorie-emission allowance could initially be set very high, say 190 calorie-credits per ounce. Reducing it slowly would give food producers time to adapt and to develop new products with lower energy densities.
The industrial production of calories has been a boon to mankind. Famine has disappeared from much of the world. Efforts to control obesity must not threaten this spectacular achievement. But the current marketplace for calories is a classic failed market: The costs of being overweight are external to food prices.
Economically, a calorie-emission trading program would have winners and losers. Some prospective losers would understand that change presents opportunity. They would welcome the program as an impetus to diversify and do the right thing for the public health. Potential losers having a narrower, self-serving vision might resist the program fiercely. We must hope that our political leaders, many of whom are sedentary, overweight and atherosclerotic, would have the courage and good health to face the barrage.
The writer is a cardiologist and chief executive of a firm working on systems to diagnose certain sleep disorders.