In this four‑week self‑experiment, Nick Norwitz consumed approximately 3,571 kcal per day, with 317 g of total fat of which 222 g (≈70 % of calories) were saturated fat, while keeping carbohydrates negligible. Weekly blood draws showed that his total cholesterol and LDL‑C remained essentially unchanged despite the massive saturated‑fat load. Norwitz attributes this resistance to his “lean mass hyperresponder” (LMHR) phenotype—lean, insulin‑sensitive individuals on a ketogenic diet who up‑regulate fat trafficking and whose LDL levels are driven primarily by energy demand rather than dietary saturated fat. He cites a meta‑analysis of 41 RCTs indicating that a low BMI is a five‑fold stronger predictor of LDL rise on low‑carb diets than high saturated‑fat intake. Throughout the video he challenges the conventional saturated‑fat‑cholesterol dogma, promotes the value of n=1 self‑experimentation, and briefly markets a handheld cholesterol analyzer (CardioCheck) with a discount code. The narrative blends personal anecdote, mechanistic biochemistry, epidemiological evidence, and a call for critical, individualized thinking about metabolic health.
Chapters
For 4 weeks, I ate 2,000 calories per day from saturated fat alone to see what would happen to my cholesterol levels. And spoiler alert: absolutely nothing. That's right, at 222 grams of saturated fat per day, my total and LDL "bad cholesterol" levels remained as flat as a week-old soda. Now, You're probably thinking to yourself, this is just clickbait. Well, you butter believe this is clickbait, but not just. You can have an engaging hook and cool metabolic demonstration backed by legitimate science meant to provoke your curiosity and be worth your time. I'm going to explain the biology of what happened, challenge you to think, and then tallow you why these results aren't just important, but pivotal. So hold on to your hamburgers. This is going to get crazy. First, let me describe my baseline diet. I eat a low-carb ketogenic diet year-round, but typically one rich in unsaturated fat, with my major fat sources being extra virgin olive oil, I'm truly an EVOO fiend, along with macadamia and macadamia butter. So, while my diet at baseline is high fat, it's high monounsaturated fat. At least 2/3 of my baseline fat intake is unsaturated, and usually more. But over the last month, I went ham on saturated fat, which is ironic because ham wasn't nearly high enough in saturated fat to hit my target. Pork fat, or lard, is only about 40% saturated fat. But to hit that 2,000-calorie mark and be sustainable for the month, my diet needed to be at least 80% fat, 70% of which would be saturated. That means I really leaned into dairy and coconut. And honestly, It was super satiating. I didn't expect that. It truly surprised me, but I struggled to get in my daily 3,571 total calories eating all that coconut butter and cheese. So I had to get creative. I blended eggs, egg yolks, coconut butter, cream cheese, and Carnivore Vanilla protein powder together into slurries and fried them into omelets so fatty It could have made skim milk cry. And if you're wondering about the vanilla protein powder, the sweet from the dash of stevia with the fat helped stimulate my appetite and made the intake possible and sustainable over the month. Altogether, my daily intake was 3,571 total calories with 317 grams of total fat, 222 grams of saturated fat, and about 170 grams of protein. With negligible carbohydrates. I tested my blood weekly and counter to what the status quo on saturated fat would have you believe, my total and LDL cholesterol levels remained as flat as graphene. And congrats to you if you got that, you're a giant dork like me. So, now I'm sure you're wondering, what's up? Qué pasa, Mufasa? And perhaps you're thinking, great, I'm banking this YouTube video for my next doctor's appointment so I can say to my doctor, hey, Dr. Nick gave me permission to chug butter like it's water after a marathon in the desert. Well, I am going to explain to you what happened or what I think happened and why my cholesterol levels didn't change despite the copious amounts of saturated fat I was eating. But sadly, I'm not here to offer you a dietary hall pass. That said, you're an adult, so you don't really need one anyway. You do you, as I normally say. Okay, so what's going on here? Well, in general, saturated fat can increase cholesterol levels in most people, at least in part by inhibiting LDL receptor activity at the liver. If your liver takes up fewer cholesterol-containing particles, LDL and total cholesterol levels can increase. And saturated fat can also increase the production of these LDL cholesterol-containing particles. So, if this is true, why am I resistant? Why did all the saturated fat not change my cholesterol levels? Well, there are a couple ways I could explain this, but I'll start with a provocative analogy to get your mental gears turning, and because I like provocative analogies. What happens if someone reduces their caloric intake? In theory, they should lose weight. That's what calories in, calories out dogma would tell you. But this doesn't always happen. Why? Because the body adapts. Energy expenditure can drop so that the caloric delta that you calculate might not actually manifest and your weight doesn't change. The high-level biological truth here is metabolism is adaptable. And, anthropomorphizing, if your body "wants" a particular outcome, it can generally tweak variables to get that outcome. Now, how does this analogy relate to my cholesterol change or lack thereof? Well, when I drop my carbs very low on a ketogenic diet, be that one based on extra virgin olive oil and macadamia, or one based on butter and coconut, my body upregulates trafficking of fat fuel. This is a phenotype that my colleagues and I have described now in about a dozen papers termed the lean mass hyperresponder, LMHR, typically people on a ketogenic diet that are lean and insulin sensitive. Basically, the leaner and more insulin sensitive a person is, the more they ramp up fat trafficking on a ketogenic diet, and as a result, the higher their LDL goes. I'll describe this more in the video caption if you want the details. And if you really want my specific values, I'll also link to some prior case reports written on myself in the notes below, so you can check those out. But the driving force of my high LDL is energy demand, and that ends up being the dominant factor controlling my LDL and total cholesterol levels such that my body appears relatively resistant, as compared to your average Joe, to saturated fat and other conventional factors. Anyway, the astute listener, hopefully you, might still be questioning, "Well, Nick, you didn't really explain why the conventional mechanism with respect to saturated fat appears not to apply to you." Well, astute audience member, You're right. Technically, I kind of diverted to make a point I wanted to make. But to your question, I'd argue that the magnitude of the saturated fat effect in me is so minimal that it's not even detectable as compared to the dominant factor of energy demands and carbohydrate intake. In fact, for those who turn their nose up at the n=1 demonstrations I do, or because they don't like the smell of brown butter— crazies— I'll point out that we, my colleagues and I, even have a meta-analysis of 41 human randomized controlled trials showing that in people who go low carb, having a lean normal BMI of less than 25 kg/m² is 5 times as powerful a factor as being in the top quartile of saturated fat intake for predicting LDL increases on a low-carb diet. So bottom line, being lean is a dominant factor over saturated fat intake for LDL rises on a low-carb diet. And being real with you, I'm significantly leaner and have higher energy demands than the average person with a BMI under 25. So to dumb it down, of all the factors impacting my LDL, saturated fat intake has such a small contribution, it's basically meaningless. It's a matter of signal-to-noise ratio, and the signal there gets lost in the noise of other factors. But now, why this stunt? It's a fair question. Since my results don't generalize to most people, what's the purpose of this demonstration? Well, first, it's to challenge inside-the-box thinking. There's a saying in medicine. When you hear hoofbeats, think horses, not zebras. I hate this saying. It's meant to suggest that the most common diagnosis or explanation is usually the right one. But, and this is my opinion now, in practice, this sort of most people, most of the time line of thinking leads to a diminution of critical thought. I say when you hear hoofbeats, turn your head and look for stripes. Then you'll learn something. We are all metabolically unique in some way, shape, or form. And it's by thinking critically about our individual cases that we can have the greatest impact. And from a scientific perspective, it's by studying the outliers and the oddballs that we learn the most. In fact, the real reason I do these profound metabolic demonstrations, one might even call them crazy, is to draw eyeballs and attention to the line of research we're doing on folks like me, lean mass hyperresponders on a ketogenic diet. Because quite honestly, we lean mass hyperresponders are such an interesting cohort. We're the scientific equivalent of a 5-star steakhouse hidden in a gas station. Unusual, but worthy of investigation. I can, for example, manipulate my cholesterol levels with dietary changes in profound ways, including dropping my cholesterol with Oreo cookies, a party trick that others, including other doctors, have since replicated. There's actually quite a lot of lean mass hyperresponders at Harvard, I'll be honest. It is not to say the findings generalize to your average person, but rather to point out the contrary— that metabolic context matters. And if we don't actively seek that context, we're being intellectually lazy and will pay the price in population health. Now for a quick but relevant diversion on n=1 science. As you probably know by now, I'm a big advocate for n=1 experimentation. I genuinely believe it's the best way to discover what works for you as an individual. And through n=1 testing, I've seen people achieve transformations that according to traditional medical training should be impossible or at least extremely rare. But that is the power of rigorous experimentation, self-experimentation. It can make you the outlier. And I know this because I've lived it personally through my own chronic diseases more than once, and seen it hundreds of times in others. Of course, when you're experimenting, it pays to have good tools. And one that I personally love for my cholesterol experiments is the CardioCheck Analyzer, which is this handy little device. This simple handheld personal-sized cholesterol meter that gives you fast readings for total cholesterol, LDL, HDL, triglycerides, as well as total cholesterol to HDL ratio, and glucose. Whenever you want, wherever you want. It is the best portable analyzer I found on the market for sure. But high-quality devices like this, admittedly, they don't come cheap. I'm not going to pretend they do. There's no way around that. But I got mine through BloodCheck Medical, which offers the lowest prices seen by a solid margin. I've checked a lot. Plus, I did reach out to them, not the other way around. I reached out to them to ask if I could get a discount code to share. And I got one $50 off, link in the video notes. Now this device is intended for healthcare professionals only. Anyway, here's to the n=1 lifestyle and taking your health into your own hands. Now, thanks for listening, back to the main video. At the end of the day, this isn't about me chugging butter for views. It's about something far more important: questioning assumptions, challenging dogma, and thinking critically about metabolic Individuality. For decades, we've been told a simple story: saturated fat raises cholesterol, cholesterol clogs arteries, end of discussion. But my experiment, along with the growing body of research on lean mass hyperresponders and just generally the growing body of research on metabolic health science, suggests the story is incomplete. Context matters, metabolism adapts, and the same rules don't apply to everyone. Now, I know this video is going to trigger some people. That's kind of the point. The data doesn't care about your emotions, but the algorithm loves them. And I like getting the word out and forcing hard, nuanced discussions. So like this video, comment, and share. Please share. You butter believe the this was clickbait. But as with saturated fat and cholesterol, I told you there was more to the story. Stay curious and sometimes stay provocative.
