It all depends on what you mean by diet. Personally, I'd call eating less calories than you use a diet, whether it's a specific plan like WW or not.
At the end of the day (wow I've just realised I type that a lot
), any plan that means taking in less calories than you use is going to result in weight loss, so long as you stick to it. Those are the key words. If you want to choose a specific plan, ask yourself the following:
- is it healthy and balanced
- is it practical
- can I do it forever.
If the answer to these is no (which it would be for me, for any specific plan) then I suggest you try the healthy lifestyle approach first. If, however, you find a plan that is flexible, cheap and practical enough to maintain consistently, and think you would benefit from the structure of following one, I don't see why you'd be setting yourself up to fail.