3 days ago I ended a 7-day water fast.
I lost 11 lbs over those 7 days and was very happy with the results. Based on my previous fasting experience I estimated about 3-4lbs of that was water weight that would return as soon as I started eating again. However, I did my weight today and I’ve gained back a total of 6lbs.
I’ve been really careful about what I eat and counting calories. I haven’t gone above the daily calories my BMR allows for maintaining weight.
Could it really be 6lbs of water weight or are my fasting weight loss expectations off?
I’m planning to do a 5 day fast every Mon-Fri of this month and had calculated that would bring me to my goal weight, but seeing this on the scale today made me think I should re-adjust my expectations.
What have people’s experiences been with weight gain after ending a long fast?
5’3” F SW: 160lbs Weight after fast: 149lbs CW: 155lbs (Not on my period)
Losing 5 pounds in 7 days is quite good for a woman of your height and weight. I certainly wouldn’t expect more than that. If anything, you’ll lose less as you get closer to your goal weight. Do you have some event you’d like to lose weight for? Personally I’d only do a 5 day fast every other week.
Assuming a TDEE of ~2000 calories, fasting for a day would create a deficit of 2000 calories, and x7 = 14,000 calories.
It’s estimated that there’s about 3,500 calories in a pound, so 14,000/3,500 = 4 lbs.
So having lost 4 or 5 lbs after a week of fasting sounds about right.
It isn’t water weight per se. It is weight of food in your intestine. Your intestine is LARGE and it is said we have 10 lbs of just food in the body at one time. I didn’t think that was true until I had a colonosopy and had to poop it all out. Wow… it was never ending.
Yup. I can vary my weight by 10 lbs in a 72 hr period depending on what I’m doing. Don’t sweat the daily weigh in. What you should care about is the trend.Just ignore daily weigh in and just average them all at the end of the week. As Long as that weekly average is going down it’s good.
Sometimes I’ll use the bathroom (#2) and lose 4 lbs. A 30 minute sauna session can make me go down 2 lbs.
It’s motivating in the middle of a fast to watch the daily weigh in number go down but all bets are off as soon as you start introducing food back into the system.
A lot of it’s going to be water. I forget the exact amount but it’s something like for every gram of glycogen stored in your body you retain however much water. Fasting depletes your glycogen stores so there’s a corresponding amount of water your body isn’t holding onto. My layman’s understanding at least.
Yes, it is normal.
You replenish your glycogen stores (about 500 g) and with that come about 1,5 kg of water. For a typical adult. So count about 2 kg (4 lbs) there.
Add a possible correction of a mild dehadration and the food in your digestive track.
It could be. I love calculating and envisioning the future and I track my weight day and night to have a better predicting power after 1-2 months.
Salt and carbs retain water in the body. Also gut microbiome should be reduced during fasting and int otal it can weigh like 2kg i read somewhere.
I have only done 2 3.5 fasts 1 week apart and the weight measurements (in kg = 2.2lbs) were like this:
| 1st day | 2nd day | 3rd day | 4th day |
|---|---|---|---|
| 128.6 | 127.8 | 127.4 | 126.3 |
| (2-day diff) | (0.8) | (0.4) | (0.9) |
| 127.8 | 126.5 | 125.8 | 125 |
| (2-day diff) | (0.7) | (0.7) | (0.8) |
| 0.8 | 1.7 | 1.6 | 1.3 |
Last line is the different of 1st day of first fast and 1st day of second fast
Yes it’s very normal but pls don’t let it discourage you! I lost 12lbs in my first 3 day fast (and I’m only 40 lbs overweight). But on the days that I eat, I gain back some of what I lost. I’m still down 8lbs from starting a month ago (8lbs out of the 12lbs initially lost). I got discouraged for a while and didn’t stick to my fasting exactly but am trying to now. I’m doing rolling 72’s. ✌️
You’re weighing at the end of your fast when your body is completely empty of food. Once start eating again, that’s going to add weight back in. It took a while for me to realize that and not get discouraged.
Yes, it’s very normal. I’d flip your assumption to 3-4lbs lost, as the general guidance is ~0.5lbs lost per 24 hours fasting. As others have stated, water and waste account for the rest. I know it’s frustrating to see the numbers on the scale go back up. You might consider using app like Happy Scale or a spreadsheet where you can focus on the trend rather than the specific day’s weight.
I fluctuate like 7lbs of water weight just like daily, i weigh myself every day and the only consistent way to measure myself I’ve found is same time everyday and then track the lows. Up to 10lbs can be water weight without anything abnormal.
Yes it’s normal. Keep in mind a lot of the weight lost is water weight, so after refeeding your body will retain the water that was depleted from glycogen stores and muscles during the fast. In my experience I usually regain 3-5 lbs after doing an extended fast, and I’ve mostly kept to the Mon-Fri weekly fasts as well.