Super-low calorie Soylent?


I have not put such a recipe together, but let us say I have a Soylent recipe that has a full nutritional profile but only 500 calories. All micros, Omegas, proteins, everything is there but a day’s batch is super-low calorie with the intention of forcing the body to burn fat to compensate.

The recipe would likely be both ketogenic and low-calorie, if for no other reason than there is a minimum protein and fat profile required to be healthy, while carbohydrates bring nothing unique to the table nutritionally (yes, most dietary carbs bring micros too, I am talking pure carb molecules here).

Such a diet would obviously cause severe fatigue, but what is your take on whether this would cause actual long-term harm to the body?

Is there a minimum number of calories a person must ingest? A maximum rate at which fat burns?

This article corroborates the common knowledge that starvation is bad primarily because of the malnutrition aspect. However, a super-low calorie Soylent would have full nutrition (minus the “having enough calories” aspect of course).

I could not find anything about the maximum rate of fat loss, other than articles saying there is a difference between weight loss and fat loss (which I already know) and that the fatter a person is, the easier it is to burn fat instead of lean body mass or water.


You are basically describing a “protein sparing modified fast”. You might also look at Lyle MacDonald’s Rapid weightloss handbook.


My understanding is that at low enough caloric intake your body stops functioning properly due to low caloric intake, micro nutrients or not.

By no means should calorie intake go below 1200 calories per day. Dropping below this level causes the body to hang onto body fat as a way to protect itself against perceived starvation. This can make it very difficult to lose more weight and could cause health problems.

Edit - I was just reading the Wikipedia page on protein sparing modified fasts and it somewhat contradicts my above stated understanding, so hopefully more people weigh in.


For the record this is mostly out of curiousity, not because I want to try it. I need at least 1,800 calories per day or I will feel horrible, and even that is pushing it.

Traditionally, the idea of a super-low calorie diet is essentially starvation and not ingesting necessary micros to keep our cells going. I am wondering if it is possible to separate those ideas, similar to how the ideas of “empty stomach” and “need energy” are separate even if they often coincide on a traditional diet.


The longest recorded fast is 382 days without intake of calories, in 1965-66. The man lost weight, from 207kg when he started, to 81kg when he was done, at a rate of about a third of a kg a day (about 2300 kcal worth of fat, though some of it was probably muscle). There were no complications and he was up and about during the fast. This was under medical supervision, DON’T TRY THIS AT HOME! But it goes to show that as long as you have fat left and you’re getting your micros, a lack of calories will not harm the body.


I’m not sure where else to post should go (but I’m probably going to keep looking), though this seems somewhat related…

…I’m not interested in a super low calorie version, but more like a 1200 calorie version. Or 1000 calorie. Or something. If I eat 2000 calories a day I’m going to gain a lot of weight, but I’m hesitant to, say… eat half the pouch for 1000 calories, then supplement with a real food snack, b/c I worry I won’t get a full proper dose of the micronutrients and whatnot. To get the ideal amount of those you’d want to consume the entire pouch.

So anyone know if Soylent is planning to make it an option to pick from different calorie counts while still including everything else?


I have 2x500 calorie meals during the day, then have a “normal food” dinner. It’s worked really well for me, and I’ve even lost weight doing it.


mhm, I thought of doing that @j8048188, but then aren’t you only getting half of the total micronutrients and stuff that Soylent provides? Unless you’re eating a super healthy balanced regular meal, seems like you’re missing out cmpared to if you could just pick a 1000 calorie version of Soylent.

Or have I got that wrong?


I figure that whatever I’m getting from Soylent is better than what I was eating/not eating before. If I’ve been able to live on what I had for 23 years, then I think that even getting 50% is better. The body is amazing in that it can survive for so long on less-than-optimal nutrition. However, I’ve found that once I’m getting better nutrition, I feel so much better. I don’t have the fog in my head like I used to.
(Also, the %DV on the pouch is what nutrition will remain after sitting for 2 years. It’s higher the newer the Soylent is.)


This article corroborates what I have heard elsewhere, that an adult male should not dip below 1,500 calories unless you are being medically supervised and even then only if absolutely necessary.

Everyone is different, maybe an excessively low calorie Soylent will be healthy for some people. I would not take that risk without speaking with a physician who understands nutrition and extreme diets.