Cholesterol, LDL and Heart Health on Carnivore

If there is one lab result that worries doctors about the carnivore diet, it is LDL cholesterol. Many people see their LDL rise after switching, sometimes modestly, sometimes to levels that would normally prompt treatment. This article explains why that happens, what the evidence says about risk, where genuine uncertainty remains, and how to approach it sensibly.

A quick primer on cholesterol

Cholesterol travels in the blood inside particles called lipoproteins. The ones most relevant to heart disease are:

LDL (low-density lipoprotein): the main carrier of cholesterol to tissues. "LDL-C" is the amount of cholesterol carried in LDL particles.
ApoB: a protein found once on each LDL particle (and on a few related particles). Measuring ApoB effectively counts the number of potentially atherogenic particles^[1].
HDL (high-density lipoprotein): involved in returning cholesterol to the liver; higher HDL is associated with lower risk, though raising HDL with drugs has not proven protective.
Triglycerides: blood fats that tend to be high with insulin resistance and high carbohydrate intake.
Lp(a): a genetically determined LDL-like particle that is an independent risk factor for heart disease and aortic stenosis^[2].

What mainstream science says about LDL

A 2017 consensus statement from the European Atherosclerosis Society reviewed evidence from genetic studies, observational studies and randomized trials and concluded that LDL is a cause of atherosclerotic cardiovascular disease, with risk related to both the level and the duration of exposure^[3]. This is one of the most thoroughly tested conclusions in medicine, and it should not be dismissed.

The open question for carnivore eaters is not whether LDL matters in general, but whether a high LDL arising from a very-low-carbohydrate diet, in an otherwise metabolically healthy person with low triglycerides and high HDL, carries the same risk as a high LDL in the general population. That question has not been answered.

What happens to lipids on low-carb and carnivore diets

Typical pattern: triglycerides fall, HDL rises, and LDL-C may go up, down, or stay the same. The response varies enormously between individuals.
In randomized trials: a 2018 study in normal-weight young adults found a low-carbohydrate, high-fat diet raised LDL cholesterol substantially over just three weeks compared with their usual diet^[4].
In the carnivore survey: among respondents who reported lipid results, median LDL-C was about 170 mg/dL, with high HDL and low triglycerides^[5].

The "lean mass hyper-responder" pattern

Some people, typically lean and physically active, see extraordinary LDL increases on carbohydrate-restricted diets, sometimes to 200 to 400 mg/dL or higher, together with very high HDL and very low triglycerides. This pattern has been labelled the "lean mass hyper-responder" (LMHR) phenotype.

A 2022 study of over 500 people on carbohydrate-restricted diets found that the rise in LDL was inversely related to body mass index: the leaner the person, the larger the LDL increase on average^[6]. The authors proposed that in lean people with low body fat stores, the liver exports more lipoprotein particles to deliver fat for energy, raising LDL as a side effect.

This is an interesting hypothesis that fits the data, and it is important because it suggests some high LDL readings on carnivore arise through a different route than in familial hypercholesterolemia. But a different mechanism does not by itself prove the particles are harmless. Critics have argued that LDL at these levels should be assumed to carry risk until proven otherwise.

What do outcome studies show?

Observational data

In an analysis of the UK Biobank presented in 2023 and published in 2024, people whose diet (from a single self-reported dietary questionnaire) resembled a low-carbohydrate, high-fat "keto-like" pattern had higher LDL and ApoB, and about twice the rate of major cardiovascular events over roughly 12 years of follow-up, compared with matched participants on a standard diet^[7]. This was a small group within a large cohort, dietary data were collected only once, and the diets were not necessarily carnivore, so this is a signal worth taking seriously rather than a definitive answer.

The KETO-CTA study, and its retraction

A study published in 2025 followed about 100 people with very high LDL on ketogenic diets using coronary CT imaging and reported that LDL and ApoB did not predict plaque progression over one year. It attracted enormous attention. However, the paper was criticised for its lack of a control group and its analysis methods, and in 2026 the journal JACC: Advances retracted it, stating that the identified errors were too great to be corrected^[8]^[9]. It should not be cited as evidence that high LDL on keto is safe.

The honest summary

There is no good long-term evidence that high LDL on a carnivore diet is harmless, and no direct long-term evidence that it is harmful in this specific context either. What we do know is that LDL causes atherosclerosis in general populations, and that the benefits of lowering it scale with how high it is and for how long.

What to track

Test	Why it matters	How often
Standard lipid panel	LDL-C, HDL-C, triglycerides, total cholesterol	Before starting, at about 3 months, then as advised
ApoB	Counts atherogenic particles; often a better risk marker than LDL-C^[1]	With lipid panels if available
Lp(a)	Genetic risk factor; recommended at least once in adulthood^[2]	Once (it barely changes with diet)
HbA1c, fasting glucose	Metabolic context	With lipids
Blood pressure	Major independent risk factor	Regularly at home
Coronary artery calcium (CAC) score	Shows existing calcified plaque; may help personalise risk	Discuss with your doctor

What to do if your LDL rises a lot

Do not ignore it. Repeat the test to confirm, and discuss it with your doctor.
Look at your overall risk. Age, family history, smoking, blood pressure, Lp(a), diabetes and existing plaque all matter.
Try dietary changes. Many people see LDL fall when they replace some butter, cream and fatty red meat with fish, poultry, eggs, and fats lower in saturated fat, or when they add back some carbohydrate. Some find the diet is working for them in other ways and choose to modify it rather than abandon it.
Consider medication if appropriate. Statins and other lipid-lowering drugs are effective, and choosing a diet does not rule them out. This is a decision to make with your doctor based on your overall risk.

The bottom line

LDL often rises on carnivore, sometimes dramatically, especially in lean people.
LDL is causally linked to heart disease in general populations; whether diet-induced high LDL in metabolically healthy people carries the same risk is unknown.
The one widely publicised study claiming high LDL on keto did not predict plaque progression has been retracted.
Track ApoB and Lp(a), assess your overall risk with your doctor, and be willing to adjust.