Answering a dietitian's negative feedback


Perhaps he was waxing Socratic.


As a programmer I find that a little inexcusable… We need to learn a new framework, language or paradigm every few months but they can’t keep up with 15 year old information?


I don’t know that it’s that they can’t keep up so much as the nutritional powers that be are so slow and overly cautious in changing their recommendations and they don’t want to go against that advice and accidentally giving bad information.


Wasn’t the study that @horsfield posted about fat intake? Cos that was published in 2013 (I think).


At the end of the day, if people are getting likes for claiming that there’s no evidence. it’s pretty pathetic.

“Specifically, it is based on the theory that consuming more fat causes the body to store more fat.”

This is not true. It is is a scientific claim that I made based on research that I read that used carbon isotope testing.

At the end of the day, if we are debating with people who use moronic phrases such as “unproven theories” and claim that it’s fine to disregard medical consensus, there is no point. Find me a sizable community of medical experts who support this ratio and I will retract my claim that it’s an “experimental diet” with some elements that are rightly identified as problematic by the clinical dietician in the original post. Sign me as ‘unconvinced’ by these laypeople’s FUD arguments.


Source? (I checked and did not find it in this thread.)


Seems like quite a few results.“high+fat”+diet

More specifically, here is one study that found positive fat balances in the short term increase in percentage of calories from fat, all other things being equal.


As much as I’d love to read 6,050 articles and report back, that ain’t gonna happen. Your previous post alluded to a specific study:

As far as I can tell, you linked an entirely different study.

Is your argument that we should be wary of a high fat diet because “it takes several days for fat oxidation to match the increased fat intake”? I could warn people off weightlifting by telling them it takes several weeks or even months to see results! The study says:

Fat oxidation increased when the subjects were eating the high-fat diet, but there was considerable individual variability in the response. This view holds that the machinery that oxidizes fat is either 1) not sufficient to match the fat load, 2) not activated in a timely fashion by a signal (or signals) necessary to oxidize fat, or 3) that intracellular fatty acid availability is decreased. Flatt (4) has argued that one mechanism for an adaptation to high-fat diets is an increase in fat stores until fat oxidation rises to meet intake. The correlation of body fat with fat oxidation supports this concept. Short-term supplementation of a standard diet with fat results in fat storage because fat oxidation only slowly adapts to the higher-fat, lower-carbohydrate diet (22). As noted in our studies and in those of Schrauwen et al (7), several days are required to achieve fat balance.

Also, we’re talking about a high % of calories from unsaturated fats with Soylent; the ratio of unsaturated to saturated fats was 0.7:1 in that study (0.7 g of unsaturated fat for each 1 g of saturated fat). Soylent 2.0’s ratio is approximately 9.25-9.5:1 (18.5-19 g unsaturated fats to 2 g saturated fats). Soylent 1.5 is not quite as good at approximately 8.2:1 (20.5 g unsaturated fats to 2.5 g saturated fats). Neither one is anything close to 0.7:1. Soylent 1.5’s unsat:sat fat ratio is 11.7 times higher than the study, and Soylent 2.0’s ratio is 13.2-13.6 times higher than the study. It’s easy to wave your hands and say that doesn’t matter, but I’d argue that it does. It’s even possible, though not likely, that unsaturated fats perform worse. We don’t have any applicable data from that study.

That study contained only six people and the high-fat diet lasted only four days. One of the p-values was 0.7. I don’t see how you could possibly draw a strong, long-term conclusion of appropriate dietary fat % from that study. Here is the energy balance graph. B = baseline diet (37% fat), with some pretty big error bars:

[Edit: removed erroneous interpretation of the above graph. Thanks @MentalNomad.] I found a different study claiming seven days to adaptation for lean people, but I didn’t take the time to read the entire thing. Neither study necessarily applies to obese people, since only lean people were studied.

tl;dr: it may take about seven days to transition to a high-fat diet.

I don’t see how that is a good reason to avoid a high-fat diet, however, unless someone was switching every few days between low-fat and high-fat diets. Even then, we can only speculate on their body’s response, since that was not a tested scenario.


You made a misinterpretation of the study, @wezalef - although your conclusion was essentially correct.

The chart you showed was the net energy balance the experiment achieved. They were attempting to make this level, but not necessarily zero. The rise or fall isn’t so much a result of the study, but an indicator of how well they did at keeping it level. They set out with their best guess at the number which would put it at zero, which was calories at 1.4 times their RMR. They ended up overfeeding a little:

But this is all largely irrelevant; it’s not the point of the study, nor is it surprising that if they ate an excess 250 calories per day they gained weight. (Reading form the scale on the right side of the chart, that’s roughly how many excess kcal they had per day.)

The point was to look at exactly how their RQ changed during the metabolic adaptation process. That’s why they were doing all this in a sealed metabolic chambers. It’s the RQ results that are really of interest…

The cool part is that the RQ measurements showed that the body’s fat metabolism adapts slowly to changes in fat intake, taking days to adjust. Moreover:

In other words, we vary greatly in how slowly our fat metabolism adapts. Speculatively, those of use whose fat metabolism is slower to ramp up may gain fat more quickly when we begin to overeat. Those whose fat metabolism ramps up quickly will gain less. And they found the latter to be associated with exercise, fitness, and lower fasting insulin levels.

In other words, exercise helps you avoid gaining fat. This is probably a significant part of why exercise is so important to keep weight off, after it has been lost via a restricted diet.


Thanks, I edited my post to remove that bit.

Hilarious bonus response: Yeah, but you spelled my name wrong!


I think one of us is misunderstanding the study you linked. From the sound of it it takes your body a few days to start burning fat again after a sudden increase in fat intake. This doesn’t mean you are gaining fat during that time. At worst you don’t lose fat till your body adjusts.



Just because japs consume soy (some fermented some unfermented) and it didnt show estrogenic effects on them doesnt mean it wont on us. Maybe something else in their diet (like green tea, lots of fish) cancels it out?, maybe their different racial makeup can handle it better? There are so many factors that come into play. So we cant assume that because it didnt affect them it wont affect us…without testing. Another thing…we are still not absolutely sure that their consumption of soy didnt show any estrogenic effects on them. If you are aware of any studies, please link.

Do you have any sources for this. Also alcoholism, whats the level of alcoholism over there?. I ask this from the point of view of the risk of fld.

@syke, all kinds. Also i am curious about the liver function of those people on keto, and of course alcohol consumption.


My cholesterol was around 200, blood sugar normal, and i was overweight. But when i reduced my fat intake (all kinds) cholesterol went down a lot, nafld disappeared and weight reduced but only by a little bit. Now you say nafld is associated with cholesterol, and cholesterol with sat and transfat and not with unsat fat. Now yes sat fat is associated with high cholesterol, but say unsat fat is not. The only unsat fat that i am aware of that raises good cholesterol is DHA, i am not aware that it lowers bad. Also i was not consuming DHA at all at that time.

Which other unsat fat lower (bad) cholesterol?


From the studies I’ve seen it seems like monounsaturated fat lowers the bad cholesterol. I will have to double check the DHA being the only polyunsaturated fat that raises good cholesterol.


Yeah, ok, good point on the soy thing, however, we are looking at an entire race here, not an individual, and dietary things of this level are not typically race selective (we are talking about pretty fundamental biological processes that are common across all mammals). In short, unless Japanese people react differently to estrogen, it is incredibly unlikely that the estrogen-like compounds in soy would affect them any differently from anyone else.

Now, you have a much better argument in the fact that we don’t have any studies proving that they are not affected by those compounds, however, I think that it would be a bit obvious if they were. I mean, the most serious concern is male breast development, which is something that has never been observed in Japanese males. If the problem is not significant enough for us to know about, it is probably not significant enough for us to care about. (Keep in mind that studies like this are conducted by feeding rats enormous amounts of the chemicals being tested. To my knowledge, no study on this has actually been done on humans, and the quantities required would scale to the point of absurdity. In short, even if this applies equally to humans, you would probably have to consume large amounts of the chemicals themselves, extracted from soy, to see any effect.)

And no, I am not aware of any studies. In fact, I am not aware of any studies on this subject targeting humans at all. Rats are typically used, because they have similar biology to humans, but doing this kind of study on humans is ethically questionable. So, all they would have to go on is observation, and thus far I know of no studies that have observed any negative side effects of consuming soy on humans. (I have not looked into this in a while, so it is possible there are some recent ones. That said, I suspect we would have already heard about any that turned anything up, given the publicity it got when scientists only theorized that soy might cause problems.)

I found a source for the 40% thing yesterday, but I don’t remember were from (and I don’t have time to find it right now). It looks like percentage of calories from oils ranges from around 30% to 40% on average though. It is as low as 25% in some places, and as high as 45% in others. The 60% I believe I read in a study done in Australia, and it was not a regional average. They had a number of individuals within their sample that consumed that much, and none of them had any health problems related to it. The study ultimately recommended lower fat intake than that (based on the minimum recommended intakes for carbs and protein), but not a lot lower (wish I could recall; the minimum values left a lot of room for flexibility).

I don’t know anything about alcoholism over there at all, but that is an interesting question. I wish I could help you (and frankly, now I am curious).

And I am curious about keto diets as well. I have heard a lot of unsubstantiated claims, sometimes from doctors that seem more like quacks, but I have not seen any serious studies on them. Most of what I have seen is personal experiences, which show only that people exist who can survive on a keto diet. I kind of suspect they are similar to vegan diets. Many people can handle them, but a significant number get seriously sick from a vegan diet. (I have a friend who’s sister tried a vegan diet, and she did all the research to do it right. She ended up very sick, and in the end she gave it up. It only took around a day for her to start recovering once she started eating meat again. It was not a religious or ideological thing. She thought it could help with some minor health problems she had. It turns out this is not uncommon, though many people get sick because they don’t do it right.)


As you insist, I will repeat. The claims of the clinical dietician, that Soylent exceeds the fat guidelines, are upheld. The American Heart Association, the Mayo Clinic, and more give clear advice about fat guidelines. When exceeding these guidelines in the diet, clinical dieticians are absolutely correct to provide this advice.

Don’t waste time to give a too long response to a single article that was mentioned to back up the comment that the short term result of the high fat diet will be fat accumulation.


I think I’ve forgotten what your original point was. If it’s that Soylent has more than 35% fat all a can say is “no duh”. If it’s that going over 35% is somehow inherently unhealthy you still haven’t proven your point.


Hahaha! Fair enough; I’m terrible with names. In my defense, that’s why I @-tagged you, and when you name filled in, I thought I selected it by hitting Tab, but I may have hit space, instead. (Probably what happened. Different text prediction systems respond differently.)

That’s exactly the point of the study - learning about the change in fat metabolism after a change in diet. The study also happens to have had a diet which was roughly 250 kcal per day above maintenance, so the subjects also gained a little fat along the way - but that wasn’t the point of the study.

On confounding factors - there’s also a very high likelihood that if you had not changed your diet in terms of what you ate, but reduced the amount of it enough to cause a a similar drop in weight, you might have also improved your test profiles.

Even on the “bad fats,” they don’t seem to be very bad unless you’re consuming a little more than you need. If you consume plenty of carbs, and you also consume plenty of fats, and those fats include “bad fats,” you have the bad effects. But if your total calorie intake is on the lean side of maintenance, or at actual restriction, those “bad fats” get torn down and used by the body in much better ways and aren’t nearly as bad for us.

(Side note: “maintenance calories” is not a point, it’s a range, because our bodies have multiple ways to adjust outside of actually gaining or losing weight.)

Note: you’re likely to find two different kinds of studies, here. Monounsaturated fat tends to lower cholesterol if it’s displacing saturated fats from an otherwise isocaloric diet. It’s a better “replacement fat” in a diet which is already causing high cholesterol. Contrast this with things like EPA, DHA, GLA, etc., which are consumed in very small quantities (as calories go) and are generally studied as a supplement to food, not a replacement of it.


No, Soylent is not exceeding the AHA’s guidelines; the AHA’s guidelines are to avoid “the bad fats, saturated and trans fats,” limiting them to below specific levels. Soylent keeps below those levels. The AHA also gives general advice about overall fats, the context of which is to help people keep bad fats low - most people don’t have the specific fat breakdown of the foods they eat, and it’s not possible for them to have exact numbers. Shooting for a general range and types of food are ways to limit the bad fats.

Here is their page on on fats; it does not specify any upper limit on overall fats:

This is their real advice; note the line at the end (emphasis mine):smile:

Again, their goal is not a particular level of “total fat.” The goal is limiting the bad fat.

In other places, they offer other specific advice:


The also provide some general guidelines for fat levels within the context of normal mixed-food diets, including a recommended range for fat intake from foods, but this is always clearly based on the understanding that mixed foods will contain both good and bad fats. The only aspects of fat that they say to limit are specifically the bad fats .

Here are some specific guidelines they provide:

Again, no limit on fat intake to 35%, just a statement that 25 to 35 percent is a good target range for healthy eating of mixed foods. They proceed to tell you what things you should actually limit.

In my experience, registered dietitians are well versed on this and well aware of the differences between overall fat intake versus bad fats. What they may not be aware of, however, is the specific fat profile of Soylent, and how that plays into the picture.


I don’t mean to be pedantic but the sources do not match your comments.

We can quote this document. It does not say that that it is fine to coinsume 40%.
Page 24 of the Dietary Guidelines for Americans says as much."

Come on guys. Is it so hard to provide a one sentence quote from the AHA that says this? In my impression, the reason it is too difficult for you guys is because you are spending much time reading between the lines. You see the words strongly advises and use that to make conclusions like no limit. Which dictionary are you reading that strongly advises means no limit? The word between indicates a delimited range, which is to say that the ends of the range are limits.