This time around is the first time in 30 years of dieting that I finally have a grasp on "this is for the rest of my life."
The first time I lost 30 pounds (150 to 120) I didn't get it. That was a diet, it was done, I lost the desired amount of weight, and when I put a few pounds on, I did the diet again. The trouble with that was...the diet was ridiculously low calorie, restrictive, and hard to stick with. It was for weight loss, not maintenance, and I had not learned to maintain.
Sometimes, we lose when we don't want to (illness, divorce, depression over something traumatic) and food is the last thing on our minds. If that happens, its easy to forget we ever had a weight issue. However, when the crisis passes, if we are prone to weight gain, we gain. At some point, I realized I'm a gainer and serial dieter. Illnesses can cause weight gain as well, also medical conditions, and that adds another layer to trying get the weight off and keep it off.
I've been a successful dieter. I've never been a successful maintainer. FINALLY, I know now that what I'm doing in the moment I'll be doing tomorrow, next week, next month, next year. Rinse, repeat.
I have not yet reached my goal of 160 and I don't know when I'll get there. I know there are bound to be slip ups along the way, and also there are going to be times when I'm doing everything right and my body won't cooperate to my liking. I can wrap my head around that now, but in the moment it appears I'm "failing", I lose my cool. That is when I have to re-rally myself and talk some sense to myself. Having this forum helps during such times.
So, yea, WW for life, or healthy eating, or calorie counting or whatever food program is sustainable. If you asked liquid diet for life? I'd say no. Nutrisystem or J.Craig for life? No. Those, to me, are for weight loss, not weight maintenance--then again, having never followed those programs, I can't speak from experience what those who have done them .... do when they have reached goal, but I would imagine they have to relearn healthy ways to eat.
I need to teach myself how to eat, and really learn the lesson, in order to maintain a healthy weight. I'm learning that now. There will be days/weeks when I buckle down and do a sprint of restrictive eating to break a plateau or just "get there" faster and move some pounds downward to stay motivated, but basically I'm making healthy choices, avoiding temptation as best as I can, and not eating out of control or way over allotted portions.
So, healthy eating forever, if we want to get and stay healthy.
As to WW forever, that's why they offer lifetime status.....

and a lifetime of weighing in and staying accountable without consequence -- unless you slip up, you pay the consequence of $ for meetings that would otherwise be free to you at LT status.