Introducing The Croissant Diet

OR: How I eliminated my spare tire by eating croissants using the six scariest words in the english language: saturated fat, insulin resistance and free radicals.

While researching for the series “The ROS Theory of Obesity“, I came across Valerie Reeves thesis via a post from Hyperlipid. She fed a group of mice a diet with an even split of carbohydrates and fat and relatively low protein. Most of the fat was stearic acid, a long chain saturated fat that is most common in beef fat, cocoa butter and dairy fat. The mice fed this diet became very lean, but in particular they had very little abdominal fat and more lean mass compared to mice fed a high starch diet or mice fed a diet high in oleic acid, a monounsaturated fat found in olive oil. The diet was described like this:

The line labelled “40% kcal stearic acid” shows the macronutrient composition of the diet that produced the lean mice – about 18% protein with 40 percent fat and 42% carbohydrate, with most (85%) of the fat being stearic acid.

I don’t know what you see when you look at that table, but I see a croissant recipe.

And so I thought, “Does this mean I could lose weight by eating croissants?!” And I’m THAT guy, so of course I did it. And it worked.

UPDATE: Check out the Croissant Diet Podcast from Biohackers Lab:

Further Reading

There’s lots to go in this post but when you’re done check out:
The Croissant Diet Specification
The Croissant Diet FAQ

How I Got Here

I’m a 44 year old man from upstate New York. I read Weston Price’s “Nutrition and Physical Degeneration” when I was 25, where I learned that white flour, white sugar and vegetable oil were “the displacing foods of modern commerce”. I first did the Atkins diet sometime around 2002. My longstanding belief that the highest quality foods are animal-based foods from animals raised on pasture with fresh air and sunshine led me to leave my job at the Berkeley Drosophila Genome Project and start a career raising pastured pigs. Over the years I designed diets for the pigs that would minimize the amount of polyunsaturated fat in the pig fat, believing polyunsaturated fat (PUFA) to be the source of many of our metabolic problems.

Bacon Without the Corn Oil!

Firebrand Meats Low-PUFA Pork CSA

Almost all american pork – conventional, organic, pastured or otherwise, is high in polyunsaturated fats. Firebrand Meats is the first American meat company specializing in making low-PUFA pork. It is a subscription based service that is shipping to all 48 continental states. It’s based on a CSA (community supported agriculture) model, which means we need a bunch of folks to sign up to get production started.

Signup is free, get a share today!

I also have a chef background. While I was living in New York after college, I was doing cancer research in a molecular biology lab at the Memorial Sloan-Kettering cancer center. I signed up for a 13-week intensive training at what was at the time the French Culinary Institute ( now the International Culinary Center). I like good food and I love food history and I love understanding regional cuisines. I’m a nerd and I will spend hours perusing historical food consumption trends from the FAO or flipping through my original manuscript of The China Health Study.

Much of the last 20 years I have spent in and out of ketosis, dabbling with intermittent fasting and attempting to eat as many nutrient rich animal foods as possible – egg yolks, bone broth, pork skin, liver (I don’t like the taste of liver, much to my personal chagrin). But I’ve also been very busy and I wouldn’t describe my personality as “disciplined” or “rigorous”. But I am “fun”! Which is to say that I cheated a lot. And I drink immoderately, mostly red wine and beer. I’ve struggled with my waistline my entire life as have most everyone in my immediate family. The last year or two I had been particularly undisciplined.

I stepped on the scale January 1st of 2019 to the shocking revelation that my BMI had swelled to over 37. Morbid obesity is defined as having a BMI over 40. I am barrel chested with thick forearms and so I carry my weight well. I stay active on the farm and I play full court basketball weekly. Still, things weren’t looking great.

Like so many Americans, I promised myself that this year would be different. I knew what to do, I would go keto. Numerous times in my life I have lost over 30 pounds on keto diets in a relatively short period of time. But I wasn’t 25 anymore and the weight didn’t come off like it used to. I spent the first half of 2019 in ketosis two thirds of the time. I was using intermittent fasting, consuming almost all of my calories between 3pm and 10pm. And I lost a little weight. But I still had a BMI of 35 and a noticeable “spare tire”, the classic symbol of male middle-aged abdominal obesity. I was still drinking dry red wine during this period but I had mostly cut out the beer. As a younger person I was always able to lose weight while drinking all of the wine I wanted.

I don’t have tons of pictures from this time period because fat people don’t like to be photographed. But there are always fish pics. On June 28th I caught a beautiful bass and my brother snapped the obligatory fish pic. And there behind the fish is my spare tire in all of its glory, after 6 months of keto, intermittent fasting and red wine.

My “spare tire” on glorious display after six months of keto and intermittent fasting. I used my friend’s Keto Mojo kit to verify my level of ketosis multiple times over the six months. This picture was taken June 28th, six weeks before beginning the croissant diet.

Also, it’s a nice bass, amiright? I caught it on a black buzzbait in a weedbed near dusk on June 28th in a lake just outside of the Adirondacks if you must know. The bass was released unharmed.

I was frustrated to the point that I agreed to do the carnivore diet with a friend. I even stopped drinking wine! Just beef and mineral water with a little pork and chicken for two weeks. And I maybe lost a lb or two? I was frustrated.

Why I Thought it Would Work

Much of this time I was researching for The ROS Theory Of Obesity. The more I read and researched and thought about The French Diet and the traditional diet of European descended farmers in the Eastern US, the more I came back to one inescapable fact.

A primary regulator of whole body energy balance is the ratio of saturated to unsaturated fat.

My long held belief that obesity was caused by carbohydrate consumption was wavering. I had always had some cognitive dissonance about low-carb dieting because, although it clearly works for a lot of people, I also know that French people in 1970 ate something like 1200 calories a day of white flour, white sugar and potatoes and remained lean. There is something to low-carb dieting but it doesn’t tell the whole story.

My research had uncovered several facts that were illuminating. 1) Mice fed stearic acid, a long chain saturated fat, lost abdominal fat, whereas mice fed oleic acid, the monounsaturated fat that makes up 70% of olive oil, gained abdominal fat, compared to low fat controls. 2) Mice who lacked the ability to convert saturated fat into monounsaturated fat had a lifetime protection against obesity. 3) Obese humans make three times as much of the enzyme that converts saturated fat into unsaturated fat and have body fat that is significantly more unsaturated.

For decades now, I have believed that polyunsaturated fat from sources such as corn oil, soybean oil, safflower oil and canola oil are a very bad idea. They are highly prone to oxidation and associated with all kinds of diseases. But the more I researched, I was coming to the inevitable conclusion that monounsaturated fat could also contribute to obesity. Monounsaturated fat has always been a kind of happy middle ground for traditional nutritionists who have moved away from promoting soybean oil and Weston A Price people who promote butter. No one ever really has anything bad to say about olive oil. But everything I learned suggested that olive oil could cause weight gain. Here is my nutshell version of how this works (once again, a shout out to Hyperlipid for figuring this out, I didn’t):

The primary mechanism by which the body stops the flow of energy into fat cells is the production of free radicals, aka Reactive Oxygen Species (ROS), at the conserved molecular bottleneck in the electron transport chain of the mitochondrial inner membrane. The ROS block the activity of several proteins involved in insulin signalling, leading the fat cells to become physiologically and reversibly insulin resistant. The job of Insulin is to send a signal to tell fat cells to store energy. If the fat cells are (temporarily) insulin resistant they won’t take in any more energy. Fat loss will occur. Long chain saturated fats create lots of ROS. Unsaturated fats don’t.

All of this suggests that obesity isn’t about carbohydrates per se, it’s about insulin signalling. Carbohydrate consumption causes insulin release and so keto diets presumably work by minimizing the release of insulin. But protein consumption ALSO causes insulin to be released. Fat consumption, especially saturated fat, enhances the insulin response to carbs and protein. So you can manage to release a lot of insulin on keto. In the mice fed the high stearic acid diet, the saturated fat was producing ROS in the mitochondria, which directly shut down insulin signalling and they lost abdominal fat. All of which is to say that maybe a diet of croissants is a more direct way of shutting down insulin than a keto diet?

Why I Worried It Wouldn’t Work

I had three primary concerns that changing the ratio of my dietary fat wouldn’t work or would work very slowly.

My first concern was what if my fat stores were already loaded with polyunsaturated fats and that my body would blend my body fat and my dietary fat into a mixture that wouldn’t produce enough ROS to generate insulin resistance in my fat cells. My understanding is that when you consume fat it is transported as a triglyceride (3 fats hooked together) from your intestine to your fat cells in a chylomicron. Only once the fats are absorbed into the fat cell do lipases in the fat cells convert the triglycerides into free fatty acids which are then used by the fat cell for fuel or released into the bloodstream for other cells to use as fuel. Do fat cells have some type of LIFO (last in, first out) mechanism for using fat, so that dietary fat is prioritized over stored fat? I still don’t know the answer to this question.

My second concern was that if I’ve largely, although certainly not entirely, been avoiding high sources of PUFA all of these years, was the thing that was causing me to be fat my own overproduction of the SCD1 protein? SCD1 is a gene that converts saturated fat into monounsaturated fat. If I was making a lot of it, maybe my fat cells would sabotage me by converting all of the precious dietary saturated fats into unsaturated fats before sending them to the mitochondria.

My final concern was that maybe I was wrong and weight loss is all about carbs and by eating croissants I’d eat too many carbs, produce too much insulin and I wouldn’t lose weight,or I’d gain weight.

I was planning on using myself as a guinea pig but I had my concerns and I wanted to stack the deck in my favor. I ordered some stearic acid so I could feed myself just how the mice were fed.

Enter The Croissants

Let’s take a brief aside to talk about WHY croissants. As I’ve already stated, I haven’t been much of a white flour fan for a very long time now. But I also put a lot of faith in French food traditions and the French eat a lot of white flour. Also, I know that white flour is very good at absorbing fat and saturated fat is the thing that makes this whole diet work. Lastly, white flour is a nutrient-poor food, but croissants are great at holding nutrient dense foods like liverwurst! I won’t eat sauteed liver but I’ll eat a liverwurst croissant sandwich.

More importantly, I was trying to prove my point that “A primary regulator of whole body energy balance is the ratio of saturated to unsaturated fat.” If I was going to make myself into a guinea pig I didn’t want anyone to accuse me of creating a diet that worked because of some other mechanism, such as that it was secretly a keto diet or that it was a gluten free diet or a grain free diet or a low food reward diet. Nope, I wanted to demonstrate that I, a person who had managed to approach morbid obesity, could lose weight by eating tasty croissant sandwiches.

Also, yes, it’s a hilarious stunt. Fine, I admitted it, are you happy now?

Fast forward two weeks from the day I began the carnivore diet and I’m in my kitchen with a five lb bag of stearic acid, a pound of butter, a bag of flour and an image of a recipe my friend sent me out of the Culinary Institute of America cookbook for making “laminated dough”, the secret to making croissants. Of course I had made croissants 20 years earlier at the French Culinary Institute. It was time to revisit my roots.

Stearic acid is a strange ingredient to cook with. It has a melting point of over 150 degrees Fahrenheit, which means that at room temperature it has a texture like candle wax. If you saute something in stearic acid and put it in your mouth while the stearic acid is still molten, it will immediately turn to wax in your mouth. It comes in a beaded form, like little grains of rice.

I didn’t really know how to proceed with this, so I just mixed a bunch of stearic acid granules into the flour to substitute for one third of the butter and made the croissant recipe. The result was… dense. The stearic acid absorbed into the flour but not in an appealing way. It was kind of like a wax impregnated croissant. If you toasted the croissants, the result was edible. I started making pizza croissants. I would cut the croissant in half, toast it, then layer it with marinara, mozzarella and pepperoni.

My plan was to completely stop drinking when I went on the croissant diet. Except that the stearic acid came on a Wednesday and I was excited to try it so I made croissants Thursday night – specifically this was Thursday, August 8th, 2019 – and I had fun weekend plans so I ate croissants all weekend and continued to drink red wine. I was going to legit start the diet on Monday, meaning no more red wine. But the scale dropped by about five pounds between Thursday morning and Sunday morning. Wow! So I figured if it ain’t broke don’t fix it and I continued to drink red wine and eat croissants. And that was how things went for two weeks.

Fixing the Stearic Acid

So cooking with something akin to parafin wax is a bit odd. I have enough of a biochemistry background to know that all fats – olive oil, butter, coconut oil, lard, corn oil, you name it – are mixtures of saturated, unsaturated and polyunsaturated fats and that the melting point of a fat is determined by the overall blend. And I went to chef school. So I starting blending.

I had to remove the water and protein from the butter to make it into a butter oil like ghee. I used some shorter chain fats to give it a more desirable, less waxy mouthfeel. I think the final product is actually quite good! It’s basically a ghee. It has very high ration of saturated to unsaturated fat, but not out of line with other natural sources. For instance, it has no more stearic acid than cocoa butter, so it’s definitely in the range of naturally consumed foods. Since the proteins have been removed, you can use it even if you have a dairy sensitivity.

It can be substituted for butter in most recipes if you take a few things into account. Butter is basically a blend of fat with 20% water and a little protein. In salted butter, the little bit of water is a salty brine that adds a lot of flavor. So if you use the butteroil in place of butter, especially in a baking application where the recipe is very precise, you should use about 20% less butteroil than you would butter and you should add a little salt and water. If you use it on toast, you may want to sprinkle on a little salt to get that buttered toast flavor.

We are currently sold out of butteroil – check back soon, we’ll have it. In the meantime, you can use the stearic acid to make your own.

The First Two Weeks

After eating the croissants, I began to feel satiation like never before. A couple times when I was hungry I would prepare two croissants but I could never finish them. I’ve always been a person who never feels strongly satiated. I only stop eating because my stomach hurts. Even then I will continue to pick at a meal. Not with the croissants. When I was done I was DONE.

I started doing intermittent fasting, but not really on purpose. I just wasn’t hungry. A couple times I just forgot about dinner. I FORGOT ABOUT dinner. I mean, I would have some wine and I would get busy doing something and then I’d go to bed. The number of times I forgot about dinner between 1997, the year I graduated college, and August 8th, 2019 was zero. The number of times I forgot about dinner the first two weeks of The Croissant Diet was three.

After the initial burst of weight loss I continued to lose weight but not as quickly. But my body changed. My waistline continued to shrink. My pants continued to get looser and I felt stronger, like I was adding muscle. Interestingly, this is the same thing that happened to the mice: the ones on the stearic acid diet had the highest lean mass in addition to the least abdominal fat. On August 24th a friend took a funny picture of me at a festival with my shirt tied up to show off my leaner belly. When he sent me the picture I actually couldn’t believe it. What happened to the spare tire?! This was after 16 days of croissants and red wine.

Astonishingly most of my spare tire was gone after two weeks of croissants.

On Monday the 26th I tried on a pair of size 34 jeans and they fit. They were actually kind of loose. In July I had bought size 36 jeans from the same style and manufacturer in the same store and they were tight. I’d like to take this moment to make a point about waist sizes in jeans. Over the years, as men’s waists have swelled, manufacturers have increased the waist sizes. A size 36 ain’t what it used to be. The tight size 36 jeans were probably more like a 40 and the size 34 was probably more like a 38. But clearly my waistline was shrinking.

A Word About Macros

Many of you are probably wondering what the breakdown of fat, carbohydrate and protein in a croissant is. I was using the recipe from Sally’s Baking Addiction except I omitted the sugar and usually I didn’t have milk so I used water and I’m too lazy to bother with the egg wash. By my calculations the macros are around 66% fat, 30% carbohydrate and 4% protein. Of course I made up for the lack of protein by filling the sandwiches with things like eggs and cheese and ham and sausage.

It strikes me that the macros of a croissant are not THAT different from the macros of The Optimal Diet, an influential high fat diet that was around at the time of the Atkins diet when low carb diets were still being called high protein diets and no one had heard the term HFLC (High Fat Low Carb). The optimal diet was created by the Polish Dr. Jan Kwasniewski and it called for around 80% of calories as fat with 10-12% as protein and 8-10% as carbohydrate. Dr. Kwasniewski loved lard as a primary fat source and of course croissants use butter which has a much higher saturated to unsaturated fat ratio than lard, which is worth digging more deeply into.

Here is a table of common fats and their ratio of saturated to unsaturated fats. I am arbitrarily saying that polyunsaturated fats are twice as problematic as monounsaturated fats and so the equation is is this:


LCSFA = Long Chain Saturated Fatty Acid, 14 carbons or longer, like in butter; UFA = Unsaturated Fatty Acid, MUFA and PUFA; MUFA = monounsaturated fatty acid, like in olive oil; PUFA = polyunsaturated Fatty Acid, like in soybean oil.

RatioStearic Acid
Coconut Oil2.832.5%
Stearic Acid Enhanced Butter Oil2.5327%
Wild Elk Backfat1.8623%
Cocoa Butter1.5333%
Beef Tallow (USDA)1.0019%
Beef fat from a Ribeye Steak0.8013%
Lard (From a pig I raised, wheat finished)0.73??
Corn Finished Lard0.5913%
Lard fed 16% Distiller’s Grains0.328%
Chicken Fat0.345%
Peanut Oil0.152%
Olive Oil0.132%
Corn Oil0.092%
Sunflower Oil0.074%

Do you see how I gamed the system by making the stearic acid enhanced butter? I took what was already the best, most nutritious source (butter is a good source of fat soluble vitamins but especially vitamin K2) of high ratio SFA/UFA and made it significantly higher. Other sources of “saturated fat” don’t compare. This is a likely reason why I wasn’t losing much weight eating carnivore but I did lose weight eating croissants. Notice how poorly chicken fat and olive oil do on this metric, but also look how much different the ratio in lard can be depending on the genetics of the pigs and what you feed them! Dry Distiller’s Grains (DDG), by the way, are what’s left over from corn once you’ve turned the starch into ethanol. Did you know that 30% of the US corn crop is turned into ethanol?! Most pigs finished in the Midwest, which is most of the pigs in the country, are finished on DDG. I’ll have much more to say about the PUFA content of meat going forward.

The Next Month

After two weeks, after seeing the photo from the festival and after trying on the smaller jeans I was convinced that the diet was working. A lot of my free time was being taken up making croissants. Shocking, I know. Croissants are a lot of work. I decided to just make pancakes instead. They’re a lot less work and it’s amazing how much butter a pancake can absorb! Three pancakes can easily absorb a stick of butter, or an equivalent amount of stearic acid butteroil. When you fry pancakes in a lot of butter they get crunchy on the outside and stay tender in the center. I served the pancakes with three fried eggs. I used a recipe from allrecipes for the pancakes. When they were done I would melt a few extra tablespoons of butter on them and drizzle them with maple syrup. Like I said before, I don’t want to be accused of the diet succeeding because it lacked food reward.

Other typical meals from this period: pasta tossed in stearic acid butteroil with sauteed vegetables and pepperoni, croquettes (recipe courtesy of fiteen spatulas) fried in stearic acid butteroil and taco salad with ground beef and tortilla chips fried in stearic acid butteroil with a heavy cream based dressing.

I also developed a system of cheats during this time. The cheats were mostly for eating out, at restaurants or at my folk’s house. The allowable cheats were steak, cheeseburgers (with the bun, of course), pizza, ice cream, margaritas and burritos. The margaritas and burritos were necessary cheats because the guys and I go to a Mexican restaurant after we play basketball every week. Eating steak and cheeseburgers allows you to go to a restaurant without being awkward. You DO have to be careful about cheeseburger toppings. Hold the mayo, please. The ice cream? Well, I love ice cream and the fat is all dairy fat and the french eat sugar so it seemed appropriate. I also went to the brewpub in town weekly (at least) and drank beer.

So I ate pancakes, pasta, cheeseburgers, pizza, ice cream, red wine and beer and I continued to lose weight and my waistline continued to decrease. And I felt stronger and stronger. I often felt like I had limitless energy in basketball. My friends noticed. One friend in particular commented a few times about how on top of my game I was. For the first time ever I felt like a skinny Frenchman from 1970 rather than a fat American from 2019. All I did was fix the fat ratio!

Warning: you WILL see a shirtless picture of a not-that-fat middle aged man if you continue to scroll down.

September third I went back to the store. I tried the size 32 jeans and they fit. I tried the size 32 jeans and they fit! I tried the size 32 jeans and they fit!!! It had been 26 days. Like I say, they were probably really a 36 but a month earlier I was a 40. I took a shirtless picture showing my belly on September 24th, about six weeks into the diet. This is a picture I NEVER would have taken leading up to the diet.

Six weeks of croissants, pizza and pancakes. I mean, I’m no swimsuit model, but in January I was approaching “morbidly obese”. Things are looking up.

A Negative Feedback Loop

When I talked about the concerns I had before I started the diet, I mentioned the fact that I might be producing too much SCD1, the enzyme that converts saturated fat into monounsaturated fat. I talked about the things that effect SCD1 expression here. But what I didn’t mention is that SCD1 is upregulated by insulin. It is in fact massively upregulated in the short term by insulin. But if we eat enough saturated fat, which knocks out insulin signalling… perhaps it’s not upregulated?

If the SCD1 level stays low, that means that when your body makes its own fat (through a process called de novo lipogenesis. Your body can only produce saturated fat, then SCD1 determines whether or not it stays saturated or becomes unsaturated) – be it from starch, sugar or alcohol – that fat will stay mainly saturated. When your body burns this mostly saturated fat it will produce ROS which will knockout insulin signalling, which will keep SCD1 levels low, which will produce more saturated fat which will knock out insulin signalling.

What a difference a month of croissants makes.

Somehow this is NOT a joke. Honestly, 2018 me is as surprised as you are.


Unfortunately my life was turned upside down in mid-September and I’ve gone back into unstructured mode and at the moment the holidays are upon me. Still I’m going to call the first phase of The Croissant Diet a success. I plan to recommit to the croissant diet immediately after the new year. I’ll let you know how it goes.

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