In this video, the presenter challenges the common belief that the rise in LDL cholesterol observed on low‑carbohydrate or ketogenic diets is caused by saturated fat from foods such as butter and cream. He structures his argument around five reasons. First, the magnitude of LDL increases in lean‑mass‑hyper‑responders on keto (often 400‑600 mg/dL) dwarfs the modest LDL bumps seen in mixed‑diet populations consuming more saturated fat, making direct extrapolation invalid. Second, the LDL rise on keto is accompanied by a characteristic triad—high HDL, high LDL, and low triglycerides—defining the lean‑mass‑hyper‑responder phenotype, which saturated‑fat explanations do not address. Third, multiple studies show an inverse relationship between body‑mass‑index (BMI) and LDL response: the leaner the individual, the larger the LDL increase, suggesting leanness, not saturated fat, drives the effect. Fourth, case reports demonstrate that very high LDL can occur on ketogenic diets that are low in saturated fat, and conversely, adding saturated‑fat‑rich calories (e.g., butter, cream, or even Oreo cookies) can markedly lower LDL, contradicting the notion that saturated fat is the culprit. Fifth, a meta‑analysis of randomized controlled trials published in the American Journal of Clinical Nutrition found that BMI is a stronger predictor of LDL change than saturated fat intake, with LDL rises confined to lean participants and declines in overweight/obese groups. Collectively, the evidence points to leanness and metabolic health—not saturated fat intake—as the primary driver of LDL elevations on low‑carb diets.
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Here are 5 reasons the saturated fat myth is dead. But hold on, I should probably define what I mean specifically by the saturated fat myth, for there are many. In this video, I'm referring to the common perception that when one goes on a low-carb diet or a ketogenic diet and their LDL skyrockets, it's because of the saturated fat found in foods like beef, cream, and butter. Cream and butter. So let's dispel that myth with 5 reasons. Here's your first reason: effect magnitude, or effect size. When people, especially lean mass hyperresponders, a topic I review in multiple other videos, go low-carb and their LDL shoots way, way up. We're talking about jumps of potentially hundreds of milligrams per deciliter, as high as 400, 500, or 600 milligrams per deciliter in some cases. By contrast, it's true that in mixed diet populations, so people eating carbs and fats and proteins in roughly equal proportions, or reasonable proportions, higher proportions in their diets, saturated fat can have a little bump on LDL comparatively, but it's kind of like saying a sea turtle can swim 6 miles per hour, therefore it can sprint at 40 miles per hour on land. The context contexts and the magnitude of effect are very different, so you can't extrapolate from mixed diet populations' little bumps in LDL to conclude that it's the butter and cream bumping LDL on low-carb diets. It just doesn't make sense in magnitude or in context. Reason 2: The triad. The increase in LDL cholesterol on ketogenic diets tends to occur coupled with increases in HDL cholesterol and drops in triglycerides. This triad—high HDL, high LDL, and low triglycerides—defines what's called the lean mass hyper-responder phenotype, which is not well explained by saturated fat intake, which primarily focuses on LDL. Building on Here's something really interesting in your reason 3. There is an inverse association between body mass index and LDL cholesterol. So LDL increases to very high levels tend to occur mostly in people who are lean and metabolically healthy and often quite active. What's more, there's actually an inverse relationship between LDL and BMI, i.e., the leaner you are, the higher your LDL tends to increase in a dose-response manner. Leaner, higher LDL. Even leaner, even higher LDL, etc. And this has now been shown in multiple studies. We had a cohort study showing it, an interventional style showing it, and most recently a meta-analysis of randomized controlled trials showing it, which is actually— I'm setting aside as reason 5 because it's so impactful. But before that, let's talk about reason 4. High LDL can occur on low saturated fat diets in a ketogenic context, and adding saturated fat can drop LDL cholesterol. So reviewing, if saturated fat were to blame for increases in LDL on ketogenic diets, then one would expect you wouldn't be able to see increases in LDL if saturated fat were kept low. However, we do see this. For example, in one case study, we found that LDL cholesterol actually hit a peak level of 5 545 mg/dL in a person who on a mixed diet has LDL in the 90s. It hit 545 on a diet that included only 1 gram of saturated fat for every 5.67 grams of unsaturated fat intake. Again, I'll repeat that: only 1 gram of saturated fat for every 5.67 grams of unsaturated fat, and yet LDL peaked at 545. Now, conversely, the flip side of this is if saturated fat were to blame, it shouldn't be possible to actually add saturated fat and drop your LDL cholesterol. But we see that as well. So friends of mine have even dropped their LDL cholesterol by exclusively increasing their caloric intake from high saturated fat foods like butter and cream. If you drive your caloric intake high enough through these fatty foods and your insulin in the fasting state rises, this can actually push down your LDL via the lipid energy model, which we review in other videos. And I myself, in kind of an extreme experiment, dropped my LDL cholesterol by 71% in just 16 days by adding Oreo cookies to my diet, which actually added some saturated fat to my diet. If you want to check out that really cool experiment, I want you to click below on the link to that video abstract, which, you know, is attractive quite a bit of attention, and I think rightfully so. So please engage there as well. Our last reason, reason 5, is that meta-analysis of randomized controlled trials to which I referred. So in the perceived hierarchy of research, you kind of have randomized controlled trials, human randomized controlled trials at the top, but right above that is if you analyze a bunch of human randomized controlled trials. This is called a meta-analysis of randomized controlled trials, and we did just that in a recent study published in the American Journal of Clinical Nutrition. And what we found was stunning, that LDL increases particularly in those studies with lean people. It does not increase in studies on overweight or class 1 obesity subjects, and actually decreases in individuals, or on studies of individuals with class 2 obesity. And what's more, we found again a dose-response curve whereby people who are leaner have larger increases in LDL. And in a comparative analysis looking at BMI versus saturated fat, BMI dominated— being leaner dominated as a driver of high LDL cholesterol as compared to saturated fat. So all this collectively is telling us that the driver of high LDL on low-carb diets, it's not the saturated fat, at least not at these very, very high LDL levels. It's actually being lean and metabolically healthy, which is really interesting, isn't it? So I guess the question you really have to ask yourself is, do you still think the saturated fat is to blame?
