"Weight control is not really a 'clinical' issue," said Katz. "It plays out in parks and playgrounds, offices and schools, kitchens and cafeterias. While clinicians can, and should, be part of the solution, we can never be more than part of the solution."
And while no food is off-limits, a points system for foods allows a person to maintain portion control.
"Weight Watchers sort of decriminalizes eating," said Ayoob. "It teaches how to play the hand you're dealt with in terms of weight and body image. And that seems to work for people."
About 1 billion people worldwide are overweight, and 300 million are obese, according to the World Health Organization. To solve the problem, nutrition experts note, even small incremental weight loss can dramatically change the landscape of the obesity epidemic, and the public health outcomes that come along with excessive weight.