Is it impossible to keep weight off?

In addition to the other bits of good advice on here, whether or not you get to a good/healthy weight (or, more accurately, body fat percentage) also seems to play a major role. Most studies that show that weight loss is not sustainable, if you dig into the data you'll find that most of the participants were still overweight even at their lowest weight. People who actually get down to a lower body fat percentage seem to have a much easier time keeping the weight off.

This is likely due to a combination of several factors. There are hormonal changes that occur when your level of adipose tissue goes below certain thresholds. People who are motivated enough to actually lose that last 20-30 lbs are probably more likely to remain motivated than those that run out of steam. There are probably other issues at play here too.

Speaking from experience, coming from about 50 lbs overweight, losing the first 20-30 lbs is not easy, but really it's not all _that_ hard either. This seems to be fairly true for most otherwise healthy adults. It takes some effort, for sure, and I'm not trying to belittle anyone's effort because losing those 20-30 lbs is a great thing, but all it takes is some moderation in food intake and some exercise. Getting rid of that last bit of weight is much, much harder (I know, I'm still working on it). But, anecdotally, losing that last bit of weight seems to make it much easier to keep the weight off long-term.

I've lost 40 lbs and have kept it off (and lost) for over 2 years. It's very simple. Exercise very strenuously and do it at least 3 days a week. When I say strenuously, I mean so hard you think you will die. People do not exercise hard enough and convince themselves they are doing something useful.

It's really fun and once you are fit it is easier to tolerate. Don't be a baby. YOU NEED TO SUFFER.

(also, I lost most of my weight in the winter with a very low exercise level. It is very hard to lose weight when you are exercising hard, you just get too hungry and you can't control what you want.)

Don't go out to eat.
don't "celebrate' food, it's just fuel
eat raw
have lot's of sex (it's just fun)

Its not obsession more like conscious, mindfulness. But I think thats for any healthy person whether its weight loss or better eating, its about looking at the food options and making choices not just eating mindlessly.

Best tips I can give for maintenance (I've only been doing it for 1 year with some minor fluctuation):
1. ALWAYS be mindful of what you eat and pay attention to triggers and old habits creeping in
2. Weigh daily or every other day (some say that obsessive but I say its the best tool for prevention - if I see the scale move up I know I need to reign it in)
3. Log as best as you can - it gets hard and tiring to "always" log but try
4. Stick to the same basic foods/ meals - you know the calories and macros
5. Make a "calorie splurge" worth it - so many times I eat something only to later regret it on the scale and in taste buds and I learned that unless its really something special or I really crave it, its not worth it.
6. On a daily basis try not to eat too much processed foods - once you start on them it can open the flood gates and its hard to kick the habit.

These are my daily "rules" and it does focus more on my eating, because I agree that like weight loss its more about what you eat than the exercise.

I've lost 40 lbs and have kept it off (and lost) for over 2 years. It's very simple. Exercise very strenuously and do it at least 3 days a week. When I say strenuously, I mean so hard you think you will die. People do not exercise hard enough and convince themselves they are doing something useful.

It's really fun and once you are fit it is easier to tolerate. Don't be a baby. YOU NEED TO SUFFER.

(also, I lost most of my weight in the winter with a very low exercise level. It is very hard to lose weight when you are exercising hard, you just get too hungry and you can't control what you want.)

Don't go out to eat.
don't "celebrate' food, it's just fuel
eat raw
have lot's of sex (it's just fun)

I don't think viewing food strictly as fuel without any enjoyment is sustainable. We're programmed to enjoy food, otherwise our ancestors would forget to eat due to other priorities, and would starve or be eaten by a predator. Food is enjoyable, we need to accept that. Also, eating out is often as much a social event as it is an eating event. We can't shun our friends simply to avoid eating the foods. Learning to make positive choices, or factor some "cheats" into our nutrition is a part of learning to maintain the weight loss. I definitely agree with the last line though. Also, all exercise is beneficial, your style has some merits for some people...personally it just makes me hate exercise even more.