Am I doomed to weight gain?

Why are you doomed to anything?

First of all you realize, I hope, that there is a difference between water weight increases and weight increases caused by the accumulation of fat.

If you increase your food intake, you will, as a minimum, have some more food circulating through your gut. I don't see how the increase in weight this represents can be viewed as a problem.

If you are glycogen depleted the extra food will, probably, replenish your glycogen. In any case, if you're trying to up-regulate hormones, carbs would seem to be your friend, and this would likely result in glycogen replenishment. Since this is an increase in lean mass, not fat, again, I don't see how this becomes a problem.

So, yes, you may see an uptick on your weight trend as you introduce more food. You know what is causing it. You know that it is helping you reach your long term goals.

Re-feeds and diet breaks are GOOD things as you get leaner.

If you are asking if you're doomed to regain all the weight you lost and then some... the answer to that is much more complicated and no-one (certainly not me) has a complete answer.

If 80% of people fail to maintain their weight loss for 5 years... 20%(ish) of people succeed!

Given how many people lose weight by doing unsustainable things until they give up in despair... the % of people who find a more sustainable path and, perhaps, succeed out of those who do not give up in despair.... is bound to be higher than 20%. And better than the 0% of success rate of those who either never try, or who do give up in despair!

So the first steps, in my books, is to try and to not to give up in despair!

There is a re-feeds and diet breaks thread referenced in the stickies of the general forum... the first page lists a lot of useful information.