Lost over 5 pounds in 2 days on 100% Soylent-- can that be okay?


That sounds like too much weight loss too quickly to be healthy (although it’s a good thing so long as it’s healthy!), but I wanted to check in about this before I do anything about it. I did some googling and some skimming of this forum, but I’m having a hard time finding anything to suggest this definitely is or isn’t okay.

BACKGROUND: 38-year-old male, about 5’8", should probably weigh in the low 160s (I think?), have been trying to lose weight for a while. I’ve been using Soylent for about a month but only occasionally at 100%. I also typically work out about three times a week, and I weigh myself daily.

I was recently pretty sick for about a week. (Nothing that seems related to diet/nutrition, more like cold symptoms, seemingly just something that’s been going around.) During that time, I stopped weighing myself and also ate at least one less-than-nutritious meal every day. I’d had a busy week or two before that, so I haven’t worked out in probably close to three weeks.

THREE DAYS AGO: Last time I had solid food.
TWO DAYS AGO: Weighed myself for the first time in a while, came in at 185.2. Did 100% Soylent (plus coffee).
YESTERDAY: Weighed 182.6, did 100% Soylent (plus tea)-- first time ever doing it two days in a row.
TODAY: Weighed 179.8, planning on 100% Soylent (plus tea).

So… like I said, this weight loss is great news so long as it’s healthy, but losing over five pounds in two days seems crazy! I chalked up yesterday’s loss to being back on a healthy diet after a few days of burgers and fries, but today’s loss has me slightly concerned. I feel great (aside from still having a cough and some congestion), but I want to make sure I’m not setting myself up for problems. Is this just how going 100% on a consistent basis when you’re overweight works? Could this just be water weight?

Thanks for any feedback, it’s appreciated!


It’s just little stuff like the weight of food and total water. You can’t lose muscle, fat, or bone mass that fast. If you continue on an all Soylent diet, your weight will stabilize after a few days to a week. Regardless, it’s a normal thing.


Like JustSnilloc said. Weight fluctuates a lot day to day. You probably have less in your gut than before, and less fluid. Look at the week-to-week trends and not the day-to-day. You might want to make sure you’re drinking enough water.

Your goal of 160lbs is also well above dangerous weight loss, so don’t worry much as long as you’re above that. I’m the same height, weigh 145lbs, and am not particularly skinny.


If you were doing just soylent you probably just lost water that was being retained from the normal high sodium diet. 1 pizza can be well over 10lbs of water weight.


I strongly agree with this! I have eaten high sodium foods and weighed the next day to discover i had “gained” 7lbs! Then I went low sodium for a couple days and weighed after a bowel movement and all that “gained” weight was magically gone! It’s crazy how much water weight and food weight in our gut that we can retain!


As already said, its water weight.
Soylent is low on salt. Many people have reported having to add salt to their Soylent when on a 100% diet.
Maybe you could get used to it over time, but going from a super high salt American diet to soylent is a shock to your body. You will lose a lot of water weight and get headaches and whatnot.

There are many opinions on whether salt and water retention is good or bad.
I just added salt to my Soylent when I was on it 100%


TIL. Thanks, I always wondered why I would gain 2 pounds after eating restaurant food, then I would be back to normal 2 days later!


It’s alright, first weights go easily. If you continue, the weight loss will be more balanced and the last pounds will go slowly