Last month's (Feb. 2011) Scientific American had a great article on obesity and how to lose weight successfully. Here's the link to the article:
How to Fix the Obesity Crisis: Scientific American
Basically, you've got to:
-get initial assessment to determine baseline measurements and behavioral patterns, learn actual portion sizes.
--self-monitoring. Recording body weight, calories eaten, logging steps taken to give objective feedback
--behavior shifts. Making small changes at first.
--support groups. Encouragement by others works, whether that's an exercise group, a formal support group or even a virtual group.
The article also has good things to say about Weight Watchers and TOPS, and mentions the Zone diet--but all within the context of the above four steps.
No easy fixes, it seems, but permanent weight loss happens with those four steps.