Successful losers and the always thin do a lot of the same things—and they do them more frequently than failed dieters do. For the dietary strategies below, numbers reflect those who said they ate that way at least five days a week, a key tipping point, our analysis found. (Differences of less than 4 percentage points are not statistically meaningful.)

Lifetime weight history

Failed dieters

Overweight and have tried to lose, but still close to highest weight.

Always thin

Never overweight.

Successful losers

Once overweight but now at least 10 percent lighter, and have kept pounds off for at least three years.