The short answer
Cutting carbohydrate is one of the best-studied diet changes for type 2 diabetes and the cluster of problems that travels with it: high triglycerides, low HDL, a growing waist, and fat in the liver. For those conditions the evidence is strong. For autoimmune disease, gut disease, and mental health, it is early: promising case reports and pilot studies, but few controlled trials. And the carnivore diet, the strictest version, has the thinnest evidence of all, even though it generates the most dramatic stories.
That gap is the point of this guide. It walks through the research condition by condition, explains where Dr. Shawn Baker and his clinic Revero fit, and ends with a practical way to try a low-carb diet for a health reason without guessing: measure before, change one thing, and measure again. It is general information, not medical advice. If you have a chronic condition or take medication, the plan belongs with your clinician.
Why carbohydrate matters for chronic disease
Most of the conditions in this guide share a root: insulin resistance. When cells stop responding well to insulin, the pancreas compensates by making more of it. For years that works, and blood sugar looks normal. Meanwhile the liver turns surplus carbohydrate into fat, triglycerides climb, HDL falls, fat collects around the organs, and blood pressure tends to rise. Eventually the pancreas cannot keep up, and blood sugar crosses into the prediabetes and then the diabetes range.
Carbohydrate is the nutrient that raises blood sugar and insulin the most, so eating less of it eases the load directly. Blood glucose after meals falls almost immediately. Insulin levels drop, which lets the body draw on stored fat, and many people find their appetite falls too. That is why lab markers like triglycerides and fasting glucose can improve within weeks, sometimes before much weight has come off. It is also why some medications become too strong very quickly, which is the main safety issue covered below.
The spectrum: low-carb, keto, and carnivore
These are points on one line, not separate diets. A moderate low-carb diet keeps carbohydrate under about 100 to 130g a day. A ketogenic diet goes lower, usually 20 to 50g of net carbs, enough to put the body into ketosis. A carnivore diet removes plant foods entirely, so carbohydrate falls close to zero and the diet is built from meat, fish, eggs, and often dairy. Our guide to keto types covers the variations in more detail.
The distinction matters when you read the research. Almost all the controlled trials test low-carb or ketogenic diets that include vegetables. Carnivore adds a second change, removing every plant food, and its supporters argue that matters for autoimmune and gut conditions in particular. That may turn out to be right, but it has not yet been tested in a controlled trial, so the benefits seen in keto studies cannot simply be credited to carnivore, or the other way round.
Where Dr. Shawn Baker and Revero fit in
Dr. Shawn Baker is an orthopedic surgeon and probably the best-known advocate of the carnivore diet. His 2019 book, The Carnivore Diet, did more than anything else to take an all-animal-foods approach from internet forums to the mainstream. He went on to co-found Revero with its CEO, Mahsa Rostami, and serves as its chief medical officer.
Revero describes itself as an online medical clinic treating chronic conditions with clinician-led care. Members pay out of pocket and work remotely with licensed clinicians and coaches on a low-carb, animal-based nutrition plan that the company calls keto carnivore. The conditions it lists run from type 2 diabetes, obesity, and high blood pressure to Crohn's disease, psoriasis, eczema, and rheumatoid arthritis.
What is worth borrowing from the model
Whatever you think of carnivore, the structure is sound, and it is the same structure this guide recommends. According to its website, Revero tracks routine blood work, including HbA1c, fasting insulin, a lipid panel, and inflammation markers, at regular intervals, and its clinicians adjust medication as the numbers change. Treating diet as a therapy means measuring it like one. A doctor managing the medication side is what makes a very-low-carb diet safe for someone on insulin or blood pressure drugs.
What to keep in mind
The headline percentages on Revero's site, such as very high rates of reported improvement in diabetes, come mainly from the 2021 survey of 2,029 carnivore dieters described below, which Revero notes it did not conduct or fund. That survey is self-reported. As of October 2026 we could not find any peer-reviewed outcome data from Revero's own patients. That does not mean the program does not work. It means its results have not yet been independently published, so they cannot be weighed the way a trial can. MeKeto has no relationship with Revero or Dr. Baker and receives nothing for mentioning them.
The evidence, condition by condition
This table summarizes how strong the research is for carbohydrate restriction in general. It is a guide to how much confidence each claim deserves, not a list of things a diet will do for you.
| Condition | What the research looks like | Strength |
|---|---|---|
| Type 2 diabetes and prediabetes | Many randomized trials. The American Diabetes Association concluded in 2019 that reducing overall carbohydrate has the most evidence for improving blood glucose. | Strong for blood sugar |
| Obesity | Many randomized trials. Low-carb diets do at least as well as low-fat diets, often faster early on, with differences narrowing after a year or two. | Strong, not clearly better long term |
| Metabolic syndrome, high triglycerides, low HDL | Randomized trials show larger falls in triglycerides and rises in HDL than low-fat diets. | Strong |
| Fatty liver disease (MASLD) | Small controlled studies show liver fat dropping quickly, sometimes within two weeks and before much weight is lost. | Moderate |
| Drug-resistant epilepsy | Randomized trials in children. A medically supervised ketogenic diet is an established treatment, run by specialist teams. | Strong, as medical therapy |
| High blood pressure | Blood pressure often falls in low-carb trials, largely alongside weight loss. Medication may need adjusting. | Moderate |
| PCOS | Small pilot studies show better weight, insulin, and hormone markers. Larger trials are needed. | Early |
| Serious mental illness | Pilot studies, including a 2024 Stanford trial in schizophrenia and bipolar disorder, alongside usual medication. No control groups yet. | Early |
| Autoimmune disease and IBD | Surveys, case reports, and small case series, most on carnivore or carnivore-ketogenic diets. No randomized results yet. | Very early |
Type 2 diabetes: the strongest case
In 2019 the American Diabetes Association published a consensus report on nutrition for adults with diabetes or prediabetes. It found no single ideal split of carbohydrate, protein, and fat, but concluded that reducing overall carbohydrate intake has the most evidence for improving blood glucose, and it described low and very-low-carbohydrate eating as a reasonable option for some adults. For a diet that was once treated as a fad, that is a significant endorsement.
The best-known real-world test is Virta Health's program, which pairs a ketogenic diet with remote medical supervision. In its two-year study of adults with type 2 diabetes, about three-quarters were still enrolled at two years. Among them, HbA1c fell by an average of roughly 0.9 percentage points, weight fell by about 12%, and use of diabetes medications other than metformin dropped sharply, with insulin doses cut the most. The study was not randomized, and the comparison group was people who chose usual care, so it shows what is achievable with close support rather than proving the diet beats everything else.
A useful counterpoint comes from the UK's DiRECT trial, which used a very-low-calorie, low-fat formula diet instead of a low-carb one. Almost half the participants were in remission at 12 months, and those who lost the most weight did best. Put together, the lesson is that substantial weight loss is the main driver of diabetes remission, and a low-carb diet is one effective way to get there, especially for people who find it easier to stick to because hunger falls.
Metabolic syndrome, fatty liver, and PCOS
Metabolic syndrome is diagnosed when someone has three of five risk factors: a large waist, high triglycerides, low HDL, raised blood pressure, and raised fasting glucose. In a controlled trial comparing a very-low-carb diet with a low-fat diet in people with this cluster, the low-carb group saw bigger improvements in triglycerides, HDL, and insulin sensitivity, even though both groups ate fewer calories. You can check where your own numbers sit with the Metabolic Health Calculator.
Fat in the liver responds unusually fast. In one detailed study, ten people with obesity and fatty liver ate a calorie-matched low-carb diet for two weeks, and their liver fat fell substantially, well before much weight came off. It was a small, short study, but it fits a consistent picture: the liver makes fat from surplus carbohydrate, so taking the carbohydrate away takes away much of the raw material.
Polycystic ovary syndrome (PCOS) is closely tied to insulin resistance, which is why low-carb diets are a natural fit to test. A 2005 pilot study found improvements in weight, insulin, and hormone markers over six months, and later small studies point the same way. The research is still thin, so treat it as encouraging rather than settled. Our Keto PCOS Calculator sets targets with that insulin resistance in mind.
Epilepsy and mental health
The ketogenic diet began as a medical treatment, not a weight-loss plan. It was developed in the 1920s for epilepsy, and a randomized trial in children with drug-resistant epilepsy found that 38% of those on the diet had their seizures cut by more than half, compared with 6% of the control group. Medical ketogenic therapy is now an established option, run by specialist teams with careful monitoring. It is not something to attempt on your own for seizures.
That history is part of why psychiatrists are now studying ketogenic diets for serious mental illness. In a 2024 Stanford pilot study, adults with schizophrenia or bipolar disorder followed a ketogenic diet for four months while staying on their usual medication. Their metabolic health improved, and so did their psychiatric ratings. There was no control group, so it is an early signal worth testing properly, not a treatment to swap in for medication.
Carnivore: what the research actually shows
The most-cited carnivore study is a 2021 survey led by researchers at Boston Children's Hospital and Harvard Medical School. They recruited 2,029 adults who had eaten a carnivore diet for at least six months, mostly through social media. Respondents reported high satisfaction and wide-ranging improvements in health. Among those with diabetes, the median HbA1c fell by 0.4 percentage points, and most reported stopping or reducing diabetes medication, including 84% who said they had stopped oral diabetes drugs and 92% of those with type 2 diabetes who said they had stopped insulin.
Those numbers are striking, and the authors were careful about what they can and cannot show. Everything was self-reported, including lab values. The people who answered were enthusiasts who had stuck with the diet, and anyone who tried it, felt worse, and quit was not counted. There was no comparison group. The survey proves that some people live on a carnivore diet for years and feel well; it cannot tell you how likely that is for you.
Since then the evidence has grown slowly. A 2024 case series described ten people with Crohn's disease or ulcerative colitis whose symptoms and quality of life improved markedly on a carnivore-ketogenic diet, though they were selected because they had responded. Modelling studies have checked whether a carnivore diet can meet nutrient needs. A 2026 scoping review found only a handful of human studies in total, mostly case reports and surveys, and concluded the evidence is too limited to recommend the diet long term. The first randomized trials are now registered. Until they report, carnivore for chronic disease is best seen as a promising experiment, ideally run with a clinician who is tracking your labs.
The LDL question
On a very-low-carb diet, most of the standard lipid panel moves in a healthy direction: triglycerides fall, HDL rises, and the triglyceride-to-HDL ratio drops. LDL cholesterol is the exception. It often rises, and on carnivore diets it can rise a lot. In the 2021 survey, the median reported LDL was 172 mg/dL.
Researchers have described a pattern, called the lean mass hyper-responder, in which lean, active people on low-carb diets develop very high LDL alongside very high HDL and low triglycerides. One theory is that it reflects how the body transports fat for fuel when carbohydrate is scarce. Whether LDL raised this way carries the same heart risk as LDL raised on a typical diet is unresolved, and there are no long-term outcome trials to settle it.
The practical response is the same either way: get a lipid panel before you start and again after a few months, and review the change with your doctor, who can weigh it against your family history and other risk factors. If they offer an ApoB test or a coronary calcium scan, either can add useful context. An LDL of 190 mg/dL or more warrants a clinical look whatever your diet, and people with familial hypercholesterolemia should not attempt a very-low-carb or carnivore diet without specialist input.
Medication: the most important safety issue
The biggest risk of a low-carb diet for someone with a chronic condition is not the food. It is medication that suddenly becomes too strong. Because cutting carbohydrate lowers blood sugar and blood pressure within days, doses set for your old diet can overshoot.
- Insulin and sulfonylureas (such as gliclazide or glipizide) can cause dangerous lows. Clinical guides for low-carb diets often reduce these doses on the first day, under supervision, with frequent glucose checks.
- SGLT2 inhibitors (such as empagliflozin or dapagliflozin) carry an FDA warning about ketoacidosis, and a very-low-carb diet raises that risk. It can happen with near-normal blood sugar, so it is easy to miss. Prescribers often pause these drugs on a ketogenic diet.
- Blood pressure medication and diuretics may need lowering as pressure falls and the body sheds water and sodium. Dizziness on standing is a common sign.
None of this is a reason to avoid low-carb eating. It is a reason to tell your prescriber before you start, so the medication plan is ready on day one. Never stop or change a prescription on your own.
Who should not go it alone
Some people should only try a very-low-carb or carnivore diet with direct medical oversight, and some should not try it at all for now:
- Anyone taking insulin, a sulfonylurea, an SGLT2 inhibitor, or blood pressure medication.
- People with type 1 diabetes, where diet changes interact closely with insulin dosing.
- People with chronic kidney disease. Kidney guidelines generally limit protein in moderate to advanced disease, which conflicts with the high protein intake of a carnivore diet.
- Anyone pregnant or breastfeeding.
- Anyone with a current or past eating disorder, for whom a highly restrictive diet can do real harm.
- People with a history of gout, gallbladder disease, or familial hypercholesterolemia.
- Children, unless the diet is part of medically supervised ketogenic therapy.
A strict carnivore diet also raises questions about nutrients. A 2025 modelling study found that carnivore meal plans tended to fall short on several, including vitamin C, thiamin, magnesium, and calcium, with fiber close to zero. Organ meats, eggs, oily fish, and dairy close some gaps, but not all. Our Carnivore Diet Calculator and electrolyte guide cover the basics; a clinician can check your levels.
How to run a measured low-carb trial
If you and your clinician decide a low-carb diet is worth trying for a health reason, treat it like an experiment with a before and an after. This is the same approach clinics like Revero and Virta build their programs around.
- Get baseline labs. A useful set is HbA1c, fasting glucose, fasting insulin, a lipid panel (triglycerides, HDL, LDL, and ApoB if available), kidney function, and liver enzymes. Write down your weight, waist, and blood pressure on the same day.
- Plan medication changes first. Bring your prescriber the plan before day one, especially for the drugs listed above.
- Choose a level you can keep. For most metabolic goals, a well-built keto diet is enough, and it is easier to keep nutritionally complete. Some people use carnivore as a short elimination phase for gut or skin symptoms, then reintroduce foods one at a time. The Keto Macro Calculator sets daily targets for either.
- Look after electrolytes early. The first two weeks bring fast water and sodium loss. Extra salt and potassium-rich foods prevent most of the fatigue and headaches people blame on the diet.
- Retest at about three months. That is long enough for HbA1c to reflect the change. Use the same lab and the same fasting conditions as before.
- Compare and decide together. Enter both sets of results in the Metabolic Health Calculator to see what moved, then decide with your clinician whether to continue, adjust, or stop.
The bottom line
For type 2 diabetes, prediabetes, and metabolic syndrome, a low-carb diet is a well-supported option that major diabetes organizations now recognize, and it can work fast enough that medication needs to be managed from the start. For fatty liver and PCOS the evidence is promising. For autoimmune disease, gut disease, and mental health, it is early, and carnivore in particular rests mostly on surveys and case reports. Clinicians like Dr. Baker and clinics like Revero are pushing those questions forward, and the randomized trials now underway should bring clearer answers.
In the meantime, the most reliable way to find out whether this works for you is to measure it, with a clinician on your side. Start with your numbers, change one thing, and let the next set of labs tell you what happened.