Soylent too high in fat


High fat diets cause insulin resistance, and thus contributes to development of type 2 diabetes. One of the arguments I’ve seen Rob and Rosa Labs make is that the real culprit is saturated fat, and since Soylent is so high in monosaturated fats, it’s okay that it has so much fat.

However, in my recent review of nutrition studies relating to diabetes, I came across a number of references to the KANWU study:

The Kanwu study looked at the effects of replacing saturated fat with monounsaturated fats, and the impact on insulin resistance. What they found, as one would expect, is that replacing saturated fat with monosaturated fats reduced insulin resistance. HOWEVER, they found that replacing saturated fat with monounsaturated fats did not help if the individual was consuming more than 37% calories from fat. The conclusion was that if you had high-fat intake, it was bad for you regardless of what kind of fat it was – the monounsaturated fat was just as bad as saturated fat in such large quantities.

Given the evidence of the harm of high fat intake and the risk it poses for developing type 2 diabetes, when can we hope to see a lower fat formulation of Soylent?


Okay, I actually read the article and they specifically said that monounsaturated fats had no impact on insulin resistance. Only saturated fats showed that effect.

Trans fats are simply bad for you. Saturated fats aren’t good, but they’re also not bad unless you’re consuming a lot of them. Unsaturated fats are the good fats, they come in monounsaturated and polyunsaturated versions. Omega 3 fatty acids (the healthiest of all fats) are among the polyunsaturated variety.

Why should Soylent change? I for one appreciate such an easy way to incorporate healthy fats into my diet.

You’re straight up making things up when you say “The conclusion was that if you had high-fat intake, it was bad for you regardless of what kind of fat it was.”, instead they said “A beneficial impact of the fat quality on insulin sensitivity is not seen in individuals with a high fat intake.”, those are hardly the same things.


I think it’s important to understand the context of this particular study. It has been known for decades that dietary fat causes insulin resistance. Here’s some more info about that from a non-profit org about evidence-based nutrition:

The missing piece of the puzzle, however, was the question of whether it was merely saturated fat that decreased insulin sensitivity, or all fats. So the KANWU study was attempting to answer that question, by keeping fat intake constant and changing only the source of the fat.

So we already know that increasing dietary fat decreases insulin sensitivity, and we know from the KANWU study that if your dietary fat is more than 37% of your calories, substituting all the saturated fat with monounsaturated fat won’t help you.

Anecdotes don’t make for great evidence, but I will add that this jives with my own personal experience. Ever since I went from a “low-fat vegan” diet to a “vegan-with-most-of-my-calories-from-soylent” diet, my A1C has gotten worse. I am my ideal bodyweight and exercise daily; only lifestyle change was more soylent consumption. Based on the evidence on fat and insulin resistance, I think the most likely culprit is the high level of fat in Soylent.


Do you do cardio regularly?

and what is your BMI


Yes every day. 22.8.


Have you done ANY research on the effects of carbs on insulin resistance?!? Seems we are much better off with unsaturated fats.

I’ve been on 60-90% Soylent for 4 years now and not only have I lost 20lb but my LDL has dropped from 81 to 67 and my HDL is up from 85 to 113 (although that’s probably more exercise than diet). I’m 52 years old and just yesterday ran a half marathon in 1:34… I’d say Soylent is working just fine for me as is. Please don’t change it.


Yes, the research shows carbs do not cause insulin resistance, fat causes insulin resistance. Fat accumulates in the cells and this “intramyocellular fat” blocks the insulin from working. Rural societies that live on a low-fat grain-based diet don’t get type 2 diabetes. I provided a starting point link above, which leads to other papers.

Congrats on running your marathon. Be aware, Dr. Esselstyn, head of the cardiovascular prevention program at the Cleveland Clinic wellness institute has said that unless your total cholesterol is under 150, you are at risk of a heart attack. That is why he also advocates a diet with around 10% calories from fat for preventing coronary heart disease. My total cholesterol on a diet of primary soylent is probably in the same ballpark as yours, but I am not satisfied with that and want to do better. As a runner, you might be interested in checking out Dr. Garth Davis who advises a lot of marathon and triathalon athletes and bodybuilders on the benefits of high-carb, low-fat, low-protein diets.

There’s no question that Soylent is better than the standard American diet, but I want to do even better. Lower fat, higher carbs would help protect against both type 2 diabetes and heart disease. The best argument against modifying Soylent would be that all the studies showing benefit of low fat diet are in the context of unprocessed plant-based foods. It’s not entirely clear that the same benefit would be found with the kind of processed carbs that Soylent uses like maltodextrin and isomaltulose. But for the most part, Soylent drinkers buy into the philosophy that there’s nothing magical about whole foods you can’t replicate with the right ingredients. If you aren’t willing to consume processed ingredients, you wouldn’t be drinking Soylent anyway. With that in mind, it would be great to see a version of Soylent where the macronutrient profile reflects the research on preventing diabetes and heart disease.


Yes having excessive body fat can cause insulin resistance. As a healthy average weight individual I’m not really concerned about insulin resistance personally. But the bigger question for societal health is what causes body fat accumulation in the first place? From all I’ve read over the last few years it’s not from consuming fat. If anything it’s from excess carb consumption (or perhaps excessive carb and saturated fat consumption… as typifies the S.A.D.)

I’m sure there are other (lowercase) soylent products out there that more closely match your desired macronutrient profile…


To be clear, I’m not personally a nutrition expert, I’m just a guy who has researched this to the best of my ability. If you have evidence and information to the contrary, I’m always open to further reading.

I also don’t have excessive body fat and am relatively lean, and yet I have evidence that fat is accumulating in the cells of my body, for example, I have evidence of fatty liver. Perhaps it is a quirk of my genetics or metabolism that makes me especially vulnerable, but this is consistent with what I’ve read that high dietary fat can lead to an accumulation of fat in your cells, even if you are not visibly overweight.

I have read that carbs are incredibly difficult for the body to convert into fat, and that there have been studies where they force-fed people massive amounts of carbs and only a very tiny fraction of those carbs were converted to fat. I can imagine that if you consume high-levels of both carbs and fat, the readily available carb energy will cause your body to sock away all that fat. But if you don’t eat fat, it’s extremely hard to accumulate body fat.

I haven’t found alternative soylent products that match my desired macronutrient profile. Super body fuel probably comes the closest because you add oil separately, and can therefore omit it, but it’s relatively high in protein. I’m in the process of learning how to make my own homemade formulation, based on Soylent 1.3 which was the last version of Soylent in which you could control the level of fat.


VCsearch this forum for “carbs fat”… Plenty of discussions.

There are plenty of vegetarians / vegans out there that see low carb as the enemy… They of course equate high fat with animal products which obviously isn’t the only way to get lots of unsaturated fats.

Check YouTube for Peter Attia… Also lots of articles by Gary Taubes…

PS if you have fatty liver then you may be in a minority for whom a high fat diet might not be that smart…


I’m immediately wary of any clinic that has “wellness” in the name. Sure enough, they offer a number of non-medical services.



“Too often, however, I find that those who choose veganism for philosophic reasons want to find health reasons to support their diet and mix the bad science and philosophy into a bland evangelical stew they recommend for all.”

It’s like a religion…

I had heard some time back that certain fats and proteins (and vitamins and minerals) were required for survival… the one thing not required was carbs. I don’t recall the numbers but if you add up all the minimal daily fats and proteins you come up with well under 2000kcal which leaves the balance (for energy) to be supplied by fats or carbs depending on your daily energy needs. As a triathlete I typically consume 2800kcal or so a day.

If you went mostly carbs that’s fine I suppose as long as you burn all that you consume. Unused carbs are very easily turned into body fat.

Wouldn’t the ultra low fat diet this guy is promoting be dangerous?

My quest to go higher fat stems mostly from endurance sports… I’d like to be a better fat metabolizer as it would give me substantially more energy for endurance events. The body is much more eager to burn sugar (ie carbs) than fat so it needs to be trained to do so. Anyone who’s ever done endurance sports solely on sugar (Gatorade, gels etc) knows that will only get you so far…


The skeptical cardiologist ignores the many lines of converging evidence.

That particular Esselstyn study was interesting because it demonstrated an effect on extraordinarily high-risk patients. Yes it was small size, but it followed patients over 12 years, which is significant. And there have been other related studies before and since.

And if you are skeptical of Esselstyn himself, he’s certainly not the only one advocating this diet. So far in my research, I have found this is the recommendation of nearly every institute whose focus is to prevent disease through nutirition. Ornish and McDougall are other prominent nutritionist physicians who have been advocating this for decades. Consider Kempner, who was the very first doctor to every show that heart disease could be addressed through diet. His research was revolutionary, as up until that point, no one believed diet was relevant to heart disease. Know what diet he used? A strict diet of white rice and fruit juice. These days, doctors advocate a wider range of low-fat whole plant foods, but it says a lot that the earliest most conclusive results came from an extreme high carb diet.


I would question your claim that “Unused carbs are very easily turned into body fat.” My readings on de novo lipogenesis (conversion of carbs to fat) consistently say that carbs are initially converted to glycogen and only after massive amounts of unused carbs are consumed are they converted to fat, and the process itself is energy expensive and so only a small percentage would end up being converted. So, extremely difficult to get body fat from unused carbs.

The claim I consistently see is that the amount of fat occurring naturally in whole plant foods is sufficient, so not dangerous to eat such a low-fat diet. In a processed product like Soylent, they’d need to intentionally add some oil, but it appears only a very small amount is necessary. In a high-carb low-fat formulation, it seems plausible that just like the famous highly processed “rice and fruit juice diet”, Soylent would be able to reverse heart disease and type 2 diabetes. Wouldn’t that be amazing?


Fruit juice?!? You might as well just drink soda. It’s the same stuff.

Yes, carbs turn to glycogen (sugar). Then the blood sugar is regulated by insulin to turn excess sugar into fat.

FWIW I’m not a nutritionist either… I’m an engineer. Have you scanned this forum for the many fat vs carb discussions?


I have scanned the forums. I mostly see people advocating keto because they are interested in the short-term weight loss, or high protein because they think it helps with bodybuilding. I don’t see a lot of info here talking about what is the diet that is going to contribute to the longest life and greatest health, which is why I posted this topic, because it seems to me that the community of physicians looking at nutrition from that perspective have a very strong consensus towards low-fat high-carb.


Very strong consensus? This is the amazing thing about the internet… if you go down the right rabbit hole you might conclude climate change is a hoax or vaccines cause autism.

Start here:


This movie review does a nice job of breaking down what they all missed (or ignored?)

There’s also the problem that with such low fat and protein, most people won’t be able to follow the diet – or will be eating endlessly while following it.


I’m not an expert and this discussion is getting pretty technical. But I did have a conversation with a doctor not long ago about such matters, and he believes that people are all unique and do not react in the same way to various diets. So 37% fat might be just what you need, but not the right thing for me.

Personally I think that the fat content in Soylent is higher than it should be. Both the World Health Organization and the US government advocate for a lower percentage. But they are not evaluating Soylent; they are looking at average folks’ fats. However I also believe that a person with a healthy system should be able to adjust to Soylent’s formulation. I have been able to without any difficulties arising. My intake is in the 25-30% range. I am a satisfied customer but eating only Soylent strikes me as unwise.


OK, I read the movie review you linked to, although some of the finer points are hard to have an opinion on since I’ve never seen the movie Forks Over Knives.

The position of the movie reviewer seems to be, “I believe that this diet makes people healthier, but not necessarily for the reasons given in the film. Possibly these doctors just stumbled on to an effective diet by accident that happens to work, but for other reasons, like ditching processed foods and cutting back on omega 6. I’m not convinced you can’t get the same benefits while eating some meat, dairy and fish.”

The doctors in the film apparently all recommend the same basic diet for maximum health: whole-food, plant-based diet. If you’re eating a whole-food plant-based diet, the macronutrient ratio that naturally occurs in such a diet would be about 80% carbs, 10% fat, 10% protein. So indirectly, they are endorsing such a macronutrient profile.

Let’s think about this in the context of Soylent.

These doctors advocate vegan. Soylent is already vegan. No need to argue about that point, and whether it is necessary for great health.

These doctors advocate whole foods. Soylent is not whole food, it is highly processed. But there is no way it could ever not be highly processed, so again, no need to argue about this point. If you believe processed foods are inherently harmful, you shouldn’t be drinking Soylent.

So the remaining issue is macronutrients. Soylent is plant-based, but it isn’t a whole food. Nevertheless, it is certainly possibly for Soylent to do better at mimicking the macronutrient profile of a whole-food plant-based diet that is known to have such positive outcomes. Even if you think the 10% fat level recommendation by these doctors is too extreme, Soylent’s fat level is too high for all current mainstream recommendations as well (isn’t that why they got into trouble in Canada, because the Canadian govt felt the fat was too dangerously high to be called a meal replacement?), and it’s too low to satisfy the keto people. So who is Rosa Labs making happy? What science backs up this particular formulation?

To reiterate, I went down the path of researching this because I wanted to answer the question of why my own health markers were trending worse since I started drinking Soylent for the majority of my caloric intake. The nutrition science that correctly predicts the outcome I’ve personally seen says that excessive fat intake increases insulin resistance and raises cholesterol (see for more info about this).