Weight tells you far less about a person’s health than you might think (Image: Richard I’Anson/Getty)

Can you be fat and fit? Everything we think we know about obesity may be wrong – sometimes it could actually be good for you

IN 2002, cardiologist Carl Lavie began to see a confusing trend. The people he was treating for heart failure were living longer if they were obese or overweight than if they were thin. How could that be right? Obesity is notoriously bad for your heart and every other part of your body.

In the US, obesity is one of the biggest causes of preventable deaths after smoking. Worldwide, it has been linked to chronic diseases like hypertension, stroke, heart disease and type-2 diabetes. Even so, the world keeps getting fatter, a trend that may mean we will all be obese by mid-century, propelling those of us in the West ever closer to the first drop in our life expectancy since 1800.

But how much of this is true? Lavie wasn’t the only one to notice some troubling inconsistencies in the seemingly simple story. Under fresh scrutiny, conventional wisdom about the obesity epidemic is beginning to unravel, prompting some medical professionals to call for changes to everything from public policy to healthcare training.

It is small wonder we have become so obsessed with our weight. Between 1980 and 2008, body mass index (BMI) – a measure of obesity that divides weight by height squared – rose all over the world. Obesity rates nearly doubled, rising most strikingly in the US. It wasn’t hard to see where it was all heading. …