McKinsey&Company

The world is getting fat. In many countries, the proportion of people at an unhealthy weight has more than doubled in the past few decades. Globally, at least 1.3 billion adults and more than 42 million children are overweight or obese.

The consequences are considerable. Excess weight increases the risk of a wide range of illnesses, including diabetes, heart disease, and certain cancers; an estimated 2.6 million people die each year as a result of being overweight or obese. Some epidemiologists believe that excess weight will soon rival tobacco as the world’s leading cause of preventable premature deaths—the obesity pandemic’s health effects may wipe out the gains in life expectancy achieved through decreasing smoking rates.

The obesity pandemic also has significant economic consequences. The World Health Organization estimates that in many developed countries, obesity now accounts for 2 percent to 7 percent of all health care spending. Yet medical costs are only a small fraction of the pandemic’s total costs. Among its other adverse economic effects are heightened absenteeism rates, reduced worker productivity, and increased food and clothing costs.