A 20:4 plan is one of the strictest programs to go with, so not everyone has the capacity to stick with that 4-hour window .... congratulations on your weight loss
Yes as stated above to change your body shape you need to exercise.
Hello and welcome!!! I admire your desire to lose weight. I want to as well. An ongoing battle, right? I have read a lot of good things about intermittent fasting. I take it to mean, not eating for a period of specific time each day. So, stopping food intake at maybe 6 pm and going until 7 or 8 am the next day. This has gotten a lot of interest from the medical community lately although it is not a new concept at all. It does seem to have links to weight loss and overall, a positive influence on things like diabetes prevention, etc. I read an article last week that stated simply giving up a snack in the evening of around 300 calories can help your weight move in a better direction. That seems very manageable to me. And I listened to a podcast that stated basically the same. They said if you are hungry at night or in the evening to have a cup of decaffeinated hot tea. I try that. It does give me 'something' and I'm able to forego the snack. (I've always been a snacker . . . never met a cheese cake at 3 am that I didn't want to get friendly with, sad to say). Also, if you can start small and give up specific things that aren't adding to your nutrition, that can help. An example would be chips. That can be a food I mindlessly eat. So, I can say "I'm giving up chips". Then I either don't buy them although that with kids in the house and it's not just about MY diet, we will have them here. I just don't eat them. Then you can move on to crackers or whatever processed food that you tend to eat. Then you can give up sweets. Etc. Eliminate the problem foods starting with what's going to impact the most. Soda pop is a good one to give up. Eating fast food. All those things that we KNOW are not good choices, eliminate if you can. This will impact things. Right? It has to. Then work on your meals being lean. Lots of vegetables and fruits, Some fish, lean meat. Whole grains.
That's a lot. But you get the point. Start small and build this into something that works for you. Our weight is mostly a reflection of our diet. Exercise can definitely help though. If your doctor okays exercise, then even a brisk walk 5 times a week for 30 minutes will help if you start there. And you can also, if doctor cleared to do so, can add weights into your week of activities.
First, intermittent fasting can mean a lot of things -- it doesn't say how often you're going without eating. You also don't say if you're exercising. You don't say what you do eat on the days you eat. Without knowing these bits of data nobody can know what it is you're doing, how it's different from what you were doing before, why you're doing it, etc. Keep in mind that fasting doesn't necessarily result in what you're looking for -- it's origin is in pursuit of spirituality, enlightenment, and cleansing, but has become a diet fad of late. Does it work? Is it healthy long-term? Who knows? But if you're losing muscle, you're not eating the way you need to, and you're probably not exercising. If you fast too much, you're basically starving yourself on purpose, and while there are many reasons people have done this throughout history as mentioned above, building muscle tone wasn't one of the reasons.