I am not sure if this is helpful to you or not, but when I lost 100lbs fasting one 48hr period a week (about, sometimes more sometimes less) I only lost about 1.5 to 2 weeks on average. My weight would fluctuate a lot, down 8, up 6 etc., but on average over the course of many months, it was almost always averaging out to about 1.5 to 2lbs a week.
Wow I experienced almost exact same thing! I started fasting due to stomach bloat for a few weeks. Stomach bloat went down but started eating again now for one week. I quit getting on the scale but now the bloating is back maybe even more than before and I look about 5 months pregnant. For my case I think I have food intolerances/sensitivity so probably refers this week and the next fast again and then slowly add food in one at a time and keep a food journal
You mentioned you ate a lot of rice – that extra weight might be water retention from the carbs. I wouldn’t worry about it.
For me, it helps to weight myself every day at the same time and try to be “sane” around my weight. When I fast, I tend to lose up to 2 kg the first day alone!!! This shows me how much of my weight is due to water retention. And I do expect to gain that “water weight” back when I start eating again.
You fasted and lost almost 8 lbs then regained it. The bad news is those 8 lbs weren’t all fat. The good news is the regained weight will nearly all be water weight. Based on fat having 9 calories per gram, a pound of fat is about 4,000 calories. Unless you ate 30k excess calories and converted it to fat with 100% efficiency, the regained weight is not fat. I understand it’s discouraging to regain weight even if it’s water and digesting food. You probably burned between 1/4 and 1/2 pounds of actual fat per day in addition to dropping water and passing digested food. I weigh myself consistently each morning. I’ve been weight-stable for the last couple years. On average over the last year my weight has changed +/-1.2 lbs per day compared to the previous day. Yesterday I was down a full 3 pounds from the day before. Of course, that day was up 2.5. My point is there is a lot of noise and natural variability. Don’t focus too much on any one weigh in. Look at trends over time. You’re making progress. Hang in there!!