You eat what yoy need, within a 6 hour window. Fwiw you already lost about 4lbs in 3 weeks so you’re on target. Everyone applauds the u/ redditer who loses like 12 lbs in the first 18 days 😝 but 1) that’s only possible if you have like 90+ pounds to lose to begin with 2) have TERRIBLE habits like only fasting while asleep, for 8 hrs nightly, 3) also, only one school of thought is fasting works bc of calories restriction. Personally I eat anywhere from 1,200 (base need) to 2,400 calories but stay within a 4 to 6 hour window with weekly longer fasts. The key is to stop the insulin spikes caused by constantly eating.
Honestly, if you do have a problem, I would suggest it is impatience. You’ve lost around 2.5% of your bodyweight in three weeks, that is a great result. Also weight can fluctuate 5 pounds or so either direction so you’re not getting a very accurate picture of actual weight loss until you’re a few months in.
800 cal a day is almost certainly less than a dietician or trainer would have you eat, especially with 5 days a week of strength training. If you keep eating that little with exercise you will almost certainly burnout and then re-gain weight (while also potentially slowing your metabolism in the process).
You’re doing good work, just keep it up long term and aim for sustainability.
Eventually you will start to lose but maybe the body is holding onto water? I don’t think 800 calories is enough but eventually the weight will come off. Just make sure you’re not getting malnourished.
Also during my period and the week after, my weight did not really budge much, maybe pay attention to your cycle as well. I think that could have something to do with the scale numbers too.
If you think you look “pudgy” it likely has little to do with your weight, and a lot more to do with your body composition. If you forget about the scale for a while, increase your calories to a minimum of 1200 per day, and spend some time focusing on building more strength, you’ll likely achieve the aesthetic results you want, and have better overall health and longevity too. They won’t come overnight though. Time and consistency are the only way.
Doing what you are currently doing, is just going to make future gains more and more difficult as your body adapts to excessive low calorie intake. You are already experiencing this, which is why you’ve had success before, but are finding it more difficult now.