Discussion on "Grain Brain", and related claims that all carbs are unhealthy


Continuing the discussion from Soylent Macronutrient Overview:

A brief look around Google seems to show that the basic idea of this concept to be that all carbs are essentially unhealthy, and that they should only take up 5% of a “good” diet. Dr. Perlmutter also does appear, at a glance, reasonably qualified and informed.

This seems… a bit drastic, to be honest. Still, It’s an interesting claim, and probably worthy of some more discussion. What do you guys think?


I see a professionally managed blog, books for sale, and a dearth of real information. The FAQ, Q&A posts, and articles are universally geared towards sales - this bothers me right off the bat, without knowing anything more. There’s lots of buzzwords and fad support (fasting, lemon cleanses, gluten free, locally sourced, etc.)

When someone tells me there’s a crisis, and that all I have to do is make one easy payment of 29.99 to get the system that corrects the crisis, that’s a huge red flag to me.

So… character of the source aside, I’m looking for concrete information specific to his claims. http://www.happyhealthylonglife.com/happy_healthy_long_life/2013/10/grain-brain.html

Superficially, it seems a case of a doctor forgetting that correlation does not equal causation. It’s like saying remote tribal amazonians are better car drivers because their highway fatality rate in the region is 0%.

The general consensus is that gluten is not ideal, blood sugar needs to be regulated from a dietary perspective, and that working with the body’s natural metabolic machine instead of against it, your diet will keep you operating in peak physical condition. Soylent is fuel for the metabolic machine, designed with the machine in mind.

I’m definitely not sold, but I’m willing to hear more. Not gonna waste my money on the book, however. The harder someone tries to sell me something, the less I want to buy it, and this guy’s sales pitch is right up there with diamond on the Mohs scale.


LOL I have found this http://www.grainsforyourbrain.org/
Who to believe? Simply this information derive from the economic WAR between the two sides that sell different things (note the articles of retaliation against high-fat diet)


Hes a M.D. and not an actual scientist so his methods may be flawed. Technically, proteins are bad for you too as one of the products of breaking them down for energy creates a chemical that has been shown to cause gout (if I remember my metabolism class correctly), making proteins unhealthy too. It is usually true that too much of anything is bad for you, though I do not see him post any actual studies or research that suggests what number of carbs is good or bad. It is possible that carbs are better for you, but the break down of fat has products that your body may use, products in which carbs either cant make, or dont make as many of.


Carbs ultimately break down into glucose, which is used directly by your cells for energy. Some foods may have detrimental byproducts, but not carbohydrates, directly. Same for oils and protein - it’s a matter of maintaining the machine. It’s wondrously complex, but making assertions like this guy does is not very scientific. He’s ignoring the complexity and latching on to a simplistic view of poorly interpreted studies that justify his theory. I’d hazard that since he is an M.D. he’s aware of the lie in the back of his mind, but simply doesn’t care.

What he completely ignores is people who already eat balanced diets and have no ill effects. His site, book, and methodology are designed in the classic snake oil fashion. Sensationalize your subject, create fear, uncertainty, and doubt, and offer a solution… for only 3 easy payments. He missed his calling as a car salesman.


Utilizing the body’s normal metabolism - balancing carbs, protein, and fats - is the route to ideal nutrition. Yes, you can go to extremes, and in some cases (ketogenic diets) you can adapt quite well. However, you have all sorts of mechanisms built in to consume carbs, fats, and oils. Why not use everything available in a healthy, consistent manner? The idea that there’s some sort of radical adjustment you can make to your food intake that will be healthier than a balanced diet doesn’t pan out with the science.

Keto diets are gonna be better than a junk food habit. Mr. (sorry, Dr.) Sleazeball’s diet will as well. Success stories, and even entire cultures who subsist on specialist diets are used to validate the diets, and often to promote them as miracle cures.

Soylent cuts past all the crap and says “here. What you need, scientifically justified by what we know now, and no more.” It doesn’t claim to cure anything, or lower risks, or treat anything… it’s simply food, with the micros that are known to be necessary, and a good balance of macros.

There may be justification in minimizing carb intake, but that will have to be accompanied by adjusting the balance in other places. Removing them entirely is doable, but Soylent promises a path to finding a scientific optimum. Dr. Sleazeball says he already knows it. Trust him, he’s an M.D.


I am a keto’er, so I would like to point out my perspective may be a bit biased. However, I am doing keto as en experiment, it actually is the continuation of my soylent experiment.

The underlying issue in these discussions (keywords: keto, grain brain, carbohydrate and, ultimately, fat) is that the USDA recommendation (or equivalent of your area) puts a lot of emphasis on carbohydrates. A lot of people can live very healthy on a high carb diet (high carb being the USDA’s recommended 300 gram of carbs), but a different lot of people would fare better with a slightly lower amount. This heigt of this amount generally seperates the different parties in these discussions!

The recommendation of 300 gram carbs per day is not scientifically established (source: ‘Good calories, bad calories’, by G Taubes). This recommendation is based on the scientific knowledge of the fifties and sixties (1), mostly that fat “causes” heart attacks and heart attacks should be avoided at all costs. Not only is this knowledge proven incorrect in the 50 years since, but heart attack preventing diets do not lengthen the average life span: the odds of dying from certain conditions changed (cardiovascular disease decreased, cancer increased), but the overall life expectancy remained unchanged.

Next, a high intake of carbohydrates results in a high insulin response, which prevents the body from burning fats. This is the reason why a large quantity of fast carbs is bad for you: you get so much insulin in your system, that the sugar in your blood is processed (burned or stored) long before your insulin levels return to a rest state. Approximately, sugars are processed in 2 hours, while a large amount of insulin can take 4 hours to return to normal levels. This means that in these 2 hours, you are hungry even though you consumed enough calories!

A good debate discusses what levels of carbohydrates and fat are acceptable (2), and how carbs should be spread over the day. Unfortunately, most discussions concern parties trying to convince eachother that fat/carbs are bad.

Tl;dr: are carbs bad? It depends on your body type, but I (and others with me) believe that the USDA’s recommendation of 300 gram of carbs is not the optimal amount for the average population, since it was established to limit fat intake.

(1) The subject was young enough in these times, that long term studies had not been sufficiently done (i.e. they were too short, too few subject, or they didn’t actually investigate the issue of macronutrient balance).
(2) Notice that protein, the third macronutrient, is not considered. This is because we have quite a good understanding of the roles proteins play in our metabolism.


Heres a link to Dr. Lustig, from University of California, and an hour and a half long presentation on why high fructose corn syrup (HFCS) is bad and should be consumed in moderation.

Please note he actually shows and talks about the metabolic pathways of not only HFCS, but glucose and alcohol as well. He also talks about the fats they make High Density Lipid (HDL) being the good and Very Low Density Lipid (VLDL) being the bad.
From what I saw of Dr. Perlmutter’s site he doesn’t cover the metabolic pathways or do a very good job of explaining why he says grains/carbohydrates are bad.

@Rick I would like to point out that Insulin tells your bodies cells to take in glucose, which gets stored as glycogen, in cells, and that Leptin is the hunger NeuroTransmitter (NT) that lets your brain know your stomach is full.


That’s ridiculous. Leptin is a protein, not a neurotransmitter.
Other things we know about leptin:
-It’s possible for cells to develop leptin resistance. This is a hypothesis only though, but it seems likely. An experiment measured the level of serum leptin before and after study participants lost 12.5% of their body weight, and the leptin level was lower (extremely so) after the weight loss which suggests leptin resistance.
-Leptin is mainly produced by adipocytes, probably because there’s so darn many of those compared to other types of cell that produce leptin.
-Leptin is excreted; it circulates in blood.
-Leptin binds to brain cells responsible for appetite regulation. That means leptin resistance could lead to increased appetite, and lepin sensitivity could lead to decreased appetite.

Why not offer low carb Soylent and let customers decide which formula is right for them?
-Because Soylent is a new company and it’s easier to manage fewer products than more of them.
-Because the science is unproven (DEBATABLE)
-Because standard American diet Soylent is cheaper (significantly so) than low carb Soylent
-Because standard American diet Soylent tastes better
-Because certain withdrawal symptoms are experienced by a significant portion of people (around 50%) when transitioning to a low-carb diet

Still, given the opportunity, I’d choose low-carb Soylent. It would be a challenge to inform customers about the risk/benefit profile of deciding on low-carb vs high-carb Soylent.


I would hesitate to believe any claims that a particular ratio of carbs to fats to protein is preferable. We are able to establish a minimum RDA for proteins, and there doesn’t appear to be a demonstrable need for excess, aside from lifestyle. As far as lifestyle goes, there’s a well established methodical increase in protein that scales with your activity levels (re: exercise.)

One of the profound things Soylent will do is enable nutritionists and dieticians to observe the actual effects of a uniform diet on a population. Another thing Soylent does is provide a robust baseline diet which you can add on to in a highly specific way - you can supplement macros and micros in a precise way.

When they have data on the various subgroups of athletes and lifestyles among users, they’ll be able to tailor products for those groups with hard science backing them up. If it turns out that a higher ratio of fats to carbs or proteins is desirable, they’ll be able to tailor the main formula to that need.

By the way, leptin is a neurohormone, and is a key appetite regulator. It acts directly on the hypothalamus. It’s a protein for which one function is akin to neurotransmitters. The terminology in popular literature is used imprecisely, so neither of you are quite wrong, but both cases can be considered correct, depending on the perspective.


yea, I am currently in a neurobiology class, a neurotransmitter is described as existing in the pre-synaptic nerve ending, has a receptor, is unique etc. I have only head of the Leptin protein signaling controlling hunger/satiety, so I made the assumption (incorrectly it appears) that it was a specialized neurotransmitter. My bad.