A history of obesity, or how what was good became ugly and then bad.

Chronic food shortage and malnutrition have been the scourge of humankind from the dawn of history. The current worldwide epidemic of obesity, now recognized as a public health crisis, is barely a few decades old. Only after the technological advances of the eighteenth century did a gradual increase in food supply became available. The initial effect of these advances in improved public health and amount, quality, and variety of food was increased longevity and body size. These early favorable outcomes of technological advances notwithstanding, their incremental effect since the Second World War has been an overabundance of easily accessible food, coupled with reduced physical activity, that accounts for the recent increased prevalence of obesity. Obesity as a chronic disease with well-defined pathologic consequences is less than a century old. The scarcity of food throughout most of history had led to connotations that being fat was good, and that corpulence and increased "flesh" were desirable as reflected in the arts, literature, and medical opinion of the times. Only in the latter half of the nineteenth century did being fat begin to be stigmatized for aesthetic reasons, and in the twentieth century, its association with increased mortality was recognized. Whereas early reports listed obesity as a risk factor for mortality from "chronic nephritis," the subsequent recognition of the more common association of obesity with diabetes, hypertension, and heart disease altered the listings and questioned its being a risk factor for kidney disease. An enlarging body of evidence, accrued over the past decade, now indicates a direct association of obesity with chronic kidney disease and its outcomes.