Find out which popular commercial diets actually work

There's an updated review of 11 popular commercial diets and it turns out only 2 were effective for long term weight loss -- backed by scientific evidence.

The 11 diets that were looked at were Weight Watchers, Jenny Craig, Nutrisystem, Health Management Resources, Medifast, Optifast, Atkins, Slimfast and internet-based programs -- the Biggest Loser Club, E-diets and Lose It!.

The only two that helped people lose weight and keep it off were Weight Watchers and Jenny Craig. And it was a modest weight loss. Over a year's time, Jenny Craig participants lost an average of 15 pounds while those on Weight Watchers, lost 12 pounds.

With many of the other programs -- people did lose weight -- but they eventually put some of it back on.