'So few fat ones grow old': diet, health, and virtue in the golden age of rising life expectancy.

Life expectancy and chronic disease rates both rose dramatically in the United States during the first third of the twentieth century. As a result of this concurrence, Americans in this era increasingly thought about things they could do to extend their own lives, especially eating less, exercising more, and limiting stress, all factors thought to reduce chronic disease. New recognition of the correlation between daily physical habits and long lives made longevity look like a sign of virtue.