Physically active / Soylent

So, I work out 2x a week for 1hr, plus 20-30 minutes of HIIT cardio most other days. According to various online calorie calculators I should be eating around 2,300cal to maintain my weight, and I’m trying to lose maybe 5-10lbs. My body fat is currently at about 19% and I want to get to 15%.

I am experiencing extreme fatigue on Soylent… I have not felt 100% since Friday, about five days ago. There is a hint of a headache sometimes but often I just want to lay down and sleep. This is with consuming the whole pitcher over the course of a day. Right now it’s a quarter to 7 and I’m getting hungry again…

Before Soylent, I was not pigging out. I would eat a couple shakes of various stuff per day, and have one decent sized meal. My total caloric intake was about the same, maybe a bit higher but not like, 3000 or something crazy. And indeed I have been slowly losing weight over the past 6 months.

So I’m kind of wondering what might be causing this fatigue and foggy feeling. I do add the 1/4tsp of salt to the Soylent, but maybe it’s still a shock to the system coming down from maybe a much higher salt intake? The gas stuff isn’t really an issue for me… It’s really this exhaustion sensation that is the worst.

Possibly I was eating a higher protein diet before, and now it’s more carb-heavy, so my body is just burning those off quickly and leaving me starving? I did not really ever get hungry like since I started Soylent- I would actually feel full and only realize I needed to eat because I felt myself getting cranky. But I always felt full, and it wasn’t a low-carb diet either. Now I feel like I have to eat every 45 minutes. I do drink the stuff rapidly but it shouldn’t have that much of an effect… should it?

Has anyone else experienced this? Does it improve? I would like to make a real go of this stuff but it’s very hard when my body seems to be screaming at me that it’s missing something… but I don’t know what it is.

Is the idea that it’s mostly for people who are sedentary, so maybe there’s not enough protein or fats in it for people like me who are slightly more gym-ratty?


If I were you I would supplement Soylent with some protein powder.

I’m worried about this too. I rock climb 2× a week, run 2× a week, and usually lift weights once as well. I eat a lot right now and am only about 7 or 8 pounds over where I want to me (I’m 5’8", around 152-153lbs). I think it would be best to listen to your body, supplement soylent until you feel 100% - then, if you don’t lose the weight that you want to, it might make sense to fiddle with reducing the calorie intake.

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How long have you been on Soylent? How much of your diet does it make up?

If you were used to fewer carbs before I can certainly see the increase becoming an issue. I would second adding a bit of protein to see if it helps, you could also add some additional oil to help adjust the ratios further (MCT oil is great for calorie adjustments), then simply drink less of the pitcher per day if the additions raise the calories to high.

There are also some folks who are exercising regularly that may be able to give a bit more insight, a couple of threads are here and here.


If you’re working out that much you’re sweating more than average, so you may well need some more salt. Be careful also that you’re hydrating enough. It’s easy to forget you still need more fluids when you’re drinking all your meals.


I was going to recommend increasing your salt intake. I do DIY and alway have 2.5g or more of Sodium in my mix (which is “above the max” but looks to be closer to reality)

It is also possible that your required calorie estimate is low. You could try consuming more calories for a few days and seeing if that helps. The other major possibility in my mind is that you have a reaction to something like the vanillin.


I find a good way to gauge this is urine color. If it’s dark yellow you definitely need more water. One problem with air conditioned gyms is that you might not realize how much you are sweating in a vigorous workout.


@synthharp - I’m not sure I follow that line of reasoning. I understand how swimming would make one not realize they were perspiring…But if a room is cool and you don’t actually sweat as much, then you aren’t sweating as much.

Are you conflating air conditioning with air flow? Rapid evaporative cooling due to convection (IE air blowing on you constantly) could definitely mask how much you are sweating since it dries so fast, but I fail to see how simply being in a cooler room would in any way mask your sweat.

BTW, there are a lot of benefits to rapid cooling wrt working out (ability to maintain pace/exertion level longer) so I wouldn’t avoid it, just be aware of the fact that working out when you are being actively cooled by blowing air is still dehydrating you.

This is just speculation but an air conditioned gym is likely to have much lower humidity unless the climate control system includes a humidifier (unlikely) which could encourage more rapid evaporation. That’s just splitting hairs, though.

Really, I doubt dehydration would come from anything in the gym environment since OP is hardly a newbie to his workout routine. The danger with Soylent is that the liquid diet can displace the amount of water you might normally consume along with solid meals and leave you feeling hydrated when you’re definitely not, but I imagine anyone who does any kind of prolonged cardio with much intensity will tend to keep pretty close tabs on dehydration.

An air conditioned gym will most likely have lower humidity than the outside world. The whole point of perspiration is to cool our bodies through the evaporation of water. If you’re jogging outdoors on a humid day you’ll know very well how much you are sweating. I have found myself not consuming enough water when working out in air conditioned rooms because I didn’t realize how much water I was losing to perspiration, I just felt nice and cool.

you might be grossly underestimating how many calories you are burning. I wanted to loose some fat so i started counting calories and limited myself at 2000 a day… i quickly found out i had been eating close to 3k on a normal day. the 1k drop in calories intake made me feel like you described. and i lift 3 times a week and do cardio 3 times a week, so i am moderately active.

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I have to say I’ve experienced the same thing. I feel much more sluggish and tired on Soylent than I did prior to using it. Before using Soylent, I had been using one of the DIY recipes on here, which was for 2,000 calories as well. And I felt much better on it than I do on Soylent. The main reason I went to Soylent was time. Measuring out, weighing, and preparing the DIY blend was just getting to be very time-consuming. So I’m very torn on whether or not to give up on Soylent and go back to DIY or find a Plan C. But I’ve done Soylent for about 2 1/2 months now, using it for about 2 of my 3 meals per day (same as with the DIY) and it just hasn’t gotten any better.

Ditto here. The DIY People Chow 3.0.1, I consumed 1500-1750 daily and was always satiated. Now with official soylent I drink the entire 2000 kcal plus a snack in the evening to stop the hunger.

The thing is official soylent has more grams of protein than DIY Peoples Chow so I am not sure how adding even more protein (and presumable less carbs) will help.

Peoples Chow 273 g carb / 88 protein / 66 fat
Soylent 252 g carb/ 114 g protein 72 g fat

I hope someone comes up with a solution.

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Thanks everyone. I had a ‘real meal’ today for lunch and felt almost immediately better. This could be because of the large calorie dump or also because I had a lot of water… It is possible I wasn’t getting enough water before but urine color was fine so…

The trainer I use thinks that 2,000 is actually high, but some calorie calculators tell me I need 2,600. To lose some weight the idea would be, according to some, hit 1600-1800 or so, and if I tried to do that on Soylent I would be in really, really bad shape, whereas on real food I could pull that off. So clearly something is amiss.

I don’t see how burning 2000 calories a day could be high. I burn 2000 calories just by sitting in a chair (see and then generally burn 1000 calories on top of that with intense cardio (spinning). When I can limit my caloric intake to 2000 calories, that is a 7000 calorie a week deficit, which is 2 pounds of fat.

However, you are not going to be able to stay on a Soylent diet if you are hungry and/or feel like crap. I’d urge you to up your calories, as well as experiment with more water, salt, and/or protein powder. Once you’re feeling in equilibrium, then I would try to reduce the calories in a way that does not cause much discomfort.


My follow-up: I decided to re-order my DIY ingredients and see if I’m just imagining things. The change was pretty immediate. I’m not sure what ingredient in Soylent was causing me to be so lethargic, but I can confirm that moving back to DIY resolved the issue. After my breakfast and lunch on DIY, I felt noticeably more energetic. I’m very disappointed, since I loved the idea and ease (and taste!) of Soylent, but my body doesn’t seem to agree. So, as much as it pained me, I’ve decided to cancel my subscription, at least for now. The decrease in energy level was enough for me to be a deal breaker.


Official soylent isn’t working out for me as well. There is something in it (or it’s lacking something) that affects me negatively and my energy SUCKS on it. There are also the farts and headaches that won’t go away, makes it pretty hard to squat/run/bike without sharting my pants.

@bts Now that your back on your DIY any chance you could try the ingredients from Soylent one at a time and see if it affects you.

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Unfortunately, I don’t have the individual ingredients from official Soylent to try - I wish I did. I’ve been using this one:

I agree with many of the points already made here.

In an air-conditioned gym, it’s not just cooler, it’s dryer. If you work out actively, it’s easy to actually sweat and not realize how much, leading to dehydration. Also, just breathing that dry air helps dehydrate you. This is why people visiting deserts (Pheonix, Las Vegas), or people working in dry environments (like datacenters), can inadvertently get dehydrated.

When you perspire in a desert or a dry gym, the water dries quickly, but you still lose electrolytes - significant amounts of sodium and chloride, but also smaller amounts of potassium, magensium, and calcium. In a desert, it may dry on contact with the air, and you never know you’ve been sweating, but if you lick yourself, you can taste the salt on the surface of your skin. That’s why they call it a “dry heat.”

So, it’s possible that you need more water, and/or more sodium and chloride, and/or the other minor minerals. Soylent takes a minimalist approach to these minerals. I prefer to take a higher-dosage multi with my DIY.

On calories - there is substantial research proving that we humans are really bad at estimating our calorie counts by looking at and eating food. We always think we’ve eaten less than we really have. If someone thinks they’ve been consuming 2000 calories, they’ve probably been consuming 2400 or more, unless they’ve been weighing food and using a nutrition calculator app. (I’ve done this for weeks at a time, and it’s really revelatory how bad my estimates were for some meals.)

On the other hand, when you switch to Soylent, you’re getting 2000 calories per day. Very clearly.

So if you’ve been getting 2400 but thinking it’s 2000, and then you switch to really getting 2000, you should expect to feel different.

Lastly, a third effect I’ll mention… if you’ve been working out and eating gradually reduced calories and have already lost a little weight, you should expect to start feeling more fatigued as time goes by. This nearly always happens as you lose more weight. You need to continue to eat even less as you lose more weight, and this will lead to more fatigue. This is less true if you have a whole lot of weight to lose (morbidly obese), but it always kicks in as you get more lean. So part of what you’re experiencing is just a part of losing the last couple pounds that you may want to lose.

I’d agree with all the folks who suggest augmenting with some straight-up protein; in your circumstance, a little extra protein will do two things:

  1. It will be protein-sparing. I.e., preserve more muscle as you lose fat.
  2. It will enhance recovery. I.e., tough workouts will leave you less wiped out in following days.

@horsfield - I don’t have a 1:1 comparison quite yet with official Soylent, but I’ve recently switched to Schmoylent and that’s fairly close. Interestingly, while I’ve only been on it for a little over a week, I have yet to experience the same level of fatigue that I did on official Soylent. I do feel it’s valid, though, since I can literally tell within 1 day (2 max) of going back to Soylent that my energy levels have dropped significantly. I’d be very interested to know which change/substitute between them is making the difference for me.

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