Exactly the the title. I’m about to do a fast for 18+ days. I’ve done a 17 and 21 in the past and I can’t really remember how much I lost. I’m 5’9 180 would like to be 145 but I’ll take 155 lol. I’m doing this for health because of some issues but the weight loss would be such a great add on.
That’s lb and not kg, right? If that’s the case then I’m pretty sure that won’t lose that much.
Dropping down to 155 lb would require losing over a pound of fat a day, which is just not realistic for your weight. I kind of want to say 0.25~0.5lb of fat per day is viable, but even then it could be less, probably depends a lot on other biological factors other than weight. Even if you lost more during previous fasts, it gets progressively harder to drop weight the leaner you are.
Also keep in mind that in the first few days you quickly lose a lot of weight, but a lot of that is from your body retaining significantly less water and fully emptying your digestive system during a fast, but this will come back once you start eating again. It’s only a few days after the fast that you can really be sure of how much weight you actually lost, and some of that weight will be muscle and not fat.
Honestly, it’s not like you have a faster way of losing weight than not consuming any calories, so I feel like it’s somewhat pointless to be concerned about how much weight you’ll be losing. I feel like trying to estimate may just end up setting you up for disappointment.
I don’t think there’s any guessing how much weight you’ll lose, because everyone is different. And with age, your body changes, which affects fasting caloric burn rate. However, it’s probably a good idea to write down and chart your weight daily so you can reference it in the future. I found this very useful when converted into a visible graph after a year. I used a simple spreadsheet that had the date, time, weight, and a note about what I ate the night before, or any specific notes. Then you can do a simple chart or pivot table.
Or use an app.
Scale weight is not the same thing as weight loss, way too many variables. I think you have a mindset that you do 18 days and you will definitely see a number in X range on the scale. This is a poor mindset. You can probably estimate number of pounds of body fat used during the fast, but it could take a while, owing to water retention, for any of that to manifest on the scale.