Hey Uma,
Well, if added weight gain is happening from ascension and transformation and adjusting to higher frequencies, the body is really not seeing it as a negative process, even though you may not be in agreement. Most times the body views the extra weight as needed, as protection against higher frequencies that at first may seem daunting to the body. It's like a mechanism of coping, just a symptom of ascension that passes over time as the body adjusts. This means, as you are adjusting, overtime, it will go back down to normal. This also means, that finding ways to help ourselves in adjusting to the process in calm and smooth ways, can probably reverse it.

It could also be a subconscious or emotional reaction, whereas we are ascending into higher energies and we are feeling typically vulnerable. It has been written before, that when we feel unsafe, or vulnerable, or exposed it can cause weight gain, but when we feel content, at love and in peace, we are naturally at healthy weights,
and perhaps as we adjust to higher frequencies we are feeling exposed to new territory which can be threatening therefore causing weight gain.
When it comes down to it, if we can continue on our spiritual growth and feel "safe" rising into higher frequencies, then our bodies wouldn't feel the need to put on extra weight. I'm just theorizing here, because i really don't know the answers. I do know i have heard that, the actual frequencies can feel harsh at first, thus it is actually a good thing to have some cushioning. I don't think it is viewed as a negative thing.
But it makes sense, that perhaps those who are experiencing the weight gain, may be having difficulties feeling safe adjusting to higher frequencies.
I have no idea, but i was experiencing that as well. I experienced both sides, loss of appetite, and after that, random unexplained weight gain. But over time, my weight stabilized, and i am now at a healthy weight. I just continued working on my shadows, and fears that came up, going through the process calmly, and directing my energies to circulate properly, and i stopped adding on the annoying pounds.

In general, going through the process of transformation isn't exactly easy, but going with the flow is necessary, and therefore we won't experience as many unpleasant symptoms. A lot of people try to quit before they are ahead, or delay the process of transformation, trying to fight it. But if we take it easy, and listen to our bodies and what our energies are telling us, and paying attention to what else comes up... eventually the process becomes easier to move smoothly into. A lot of great minds have said, it's much like a roller coaster, of ups and downs, but as you become aware of it, and move with the flow, it becomes more smooth of a sail.

I did a lot of self love work. I tried to really focus on allowing myself to feel safe, and that reversed the weight gain process for me. I just learned to really go with the flow of the process, and deal with the insecurities that came up. My diet was the same, but at the same time, i was also going through a lot of exhaustion, tiredness and other annoying symptoms, so i wasn't working out as much. And it didn't seem to matter. I ended up trying to become obsessive about working out, forcing myself to, really beating myself up over the weight gain, which just made it worse and added on more pounds, like seriously it was five pounds a week, and made me feel even more unsafe, began eating more healthy, but the weight gain didn't care about any of that. So instead, i did the opposite, and listened to my body, took many, months of rest. I did exactly what my body wanted to do - nothing, except spiritual work. I needed a lot of rest during that period. And through my work of learning to feel safe while adjusting to all the changes, learning to love where i was at, my body sorted itself out in a matter of a few months. I lost my muscles though. Mad about that hehe. So i've been back to working out for a long while now, trying to get back my muscles, and its coming along well.