Smoking, obesity and Chesterton’s fence
The percentage of the U.S. population that smoked tobacco in 1975 was 40%. That figure has declined steadily in the intervening years, and today, only 11% of the population are smokers. Knowing what we do about tobacco’s risk to health, we can confidently identify the decline in smokers as progress in the realm of public health. However, over the same period, the percentage of the U.S. population defined as obese has climbed from 12% of the U.S. population to 42%. Rarely, does one find a correlation as striking as the inverse correlation of -.98 between the smoking and obesity rates...