The obesity epidemic makes headlines every day as journalists recite statistics about the dangers of excess body weight. Mexican food, movie popcorn and American burgers have all come under the disapproving gaze of public health advocates. Experts rail against the dangers of carrying around excess flab and warn that without drastic measures, the current generation of overweight children will become the first generation to lead shorter lives than their parents. Too often, this hatred of fat turns into hatred of fat people. With so many terrifying statistics about heart disease, type 2 diabetes, stroke, and obesity-related organ dysfunction, it's easy to conclude that any excess weight endangers people who carry it. To some extent, the concerns are justified; these risks are real at the highest levels of the weight spectrum. There is no doubt that significant excess weight contributes to serious health problems. Extreme obesity can also hinder the quality of life as well as its quantity. However, the foundation on which the concept of obesity rests – body mass index or BMI – is fundamentally flawed. Without a clear view of what constitutes overweight and obesity, it is impossible to say that any amount of excess weight is harmful. In contrast, studies of the health consequences of significantly low body weight reveal that too low a weight is as lethal as extreme obesity and considerably more dangerous than a moderately high BMI. These statistics also seem less alarming when examined more carefully, as many studies fail to distinguish between a few extra pounds and a few hundred. ...... middle of paper ...... extra pounds are healthier than being underweight by a similar amount, the prevailing attitude is that no fat is good fat. The tool that medical professionals used as a yardstick has become a tool of punishment for heavy people. More realistic assessments of the risks of excess fat are leading to changes within the medical establishment. While health professionals' views on overweight and mild obesity are evolving, the public face of obesity is slower to change. The media still focuses on the obesity epidemic and its potential costs, unfairly stigmatizing any weight gain as a public health issue rather than a personal choice. When strident warnings about the harms of butter or brownies become too deafening, it's helpful to think about the state of medicine in 1850 and remember how times have changed. Eventually the world will catch up with modern medicine.