re-gaining weight?

I need some help?!  I had RNY two years ago and lost 140 lbs.  I would like to keep my wieght between 130-135 but my body is fighting me for it!  I watch what I eat, I excercise regularly but I just can't stop gaining!  I will get to 140 then I will go on liquids until I get to about 132 and then as soon as I am eating again I am back to 140.  I don't graze, I eat high protien with a little carbs, I am not eating excessive... and I run 3-5 miles 4-5x per week!

anyone else have this problem?  any suggestions?  do i just live on liquids for the rest of my life?

thank you!

I'm 3 yrs out from RNY and Iv'e gained 7 lbs from mt lowest. I will lose them too but gain them right back, it's like my body is fighting me too. Haw tall are you? I'm 5'8''

My experience with that when we go on liquids, low carbs,  we lose some water... and once we start introducing any carbs - as our body start storing them in the muscles  and livers, and there comes back the water weight ... and we gain weight almost overnight.  My experience is that when I try to do low carb - I need to lose 5-10 lbs below where I want to be, so when I gain some back - I am in the range I want to be.  For you it looks like it is app 5-8 lbs.  so if you want to be below 135 - you may need to try to lose down to 125... if that is even possible.

I also believe that our body needs minimum body fat %, and if you get below that - the body would do almost anything to get us up there. 
Do you know what is your body fat %?  maybe it is not realistic for you to be 135? What is your lean body mass?
Mine is close to 120-130 lbs (bones, blood, water + muscles)... so unless I stop exercising and lose my muscles... or cut a limp - there is no way I could be below 140.. But that is me...