I have had exactly the same problem in the past and it has always been down to the fact that I have gone on special diets which, once I have reached my target weight, are not easy to sustain.
This time, I have done it differently (I hope). I have modified my eating habits by cutting down my portion sizes. One of the first things I did was to change the size of the plate or bowl I used to serve my food. Instead of a dinner plate, I changed to a smaller plate. For me this has worked because I have not made any drastic changes and even though my plate still looks full, it is smaller than before. I also increased the amount of vegetables and cut out the potatos. Now I do have potatos occasionally, but not with every meal and chips are now a special treat.... not an every day food.
I am still in the process of losing weight.... but I think this time I can now continue this for the rest of my life. I only lose about 1 or 2 pounds a week (and some weeks I seem to "get stuck" for a few days).
I also measure myself (bust, hips, thighs, waist and arms) so if I don't lose weight sometimes I find that I have lost inches instead and have started to exercise regularly (usually gentle bike rides or walks - nothing that I cannot continue long term)
When I have finished losing the weight I want, then I think that I will be able to maintain my portion sizes.
Hope this helps
If I can help you come up with a plan, I'll be happy to.
i wanna tell you thanks everything
If you are doing special diets or taking something to lose weight, often when you go off that diet, you regain. You should incorporate a regimen of healthy diet with portion control and adequate exercise that you can keep up on an ongoing basis. You need to make lifestyle changes that you can stick with.