LDL cholesterol often rises on a ketogenic diet, though not in everyone. In a 12-week trial of 40 adults, LDL went up by about 10% on keto but fell by about 5% on a Mediterranean-style diet, and a meta-analysis of 13 longer trials found keto raised LDL compared with low-fat diets. The usual reason is saturated fat from butter, cream, cheese and fatty meat. Choosing mostly unsaturated fats, eating plenty of fiber-rich vegetables, and getting your cholesterol checked before and after starting are the sensible steps.
What happens to cholesterol on keto
A ketogenic diet changes several blood fats at once. The pattern seen in longer trials is fairly consistent:
| Blood fat | Typical change on keto | Is that good? |
|---|---|---|
| Triglycerides | Down | Yes |
| HDL (“good”) cholesterol | Up | Generally yes |
| LDL (“bad”) cholesterol | Up in many people | No |
In the 2013 meta-analysis of 13 trials lasting at least a year, people on very low-carbohydrate ketogenic diets saw triglycerides fall and HDL rise compared with low-fat diets, but LDL rose by an average of 0.12 mmol/L (about 4.6 mg/dL). In the shorter Keto-Med trial, triglycerides fell about 16% on keto, while LDL rose about 10%.
Averages hide a wide range. Some people’s LDL barely moves, while others see a large rise. The only way to know what’s happening to yours is a blood test.
Why LDL matters
LDL is the cholesterol that can build up in artery walls. The NHS explains that eating too much saturated fat can raise LDL, which can increase the risk of heart disease and stroke. Keto’s improvements in triglycerides and HDL are welcome, but they don’t cancel out a large rise in LDL.
Why keto can raise LDL
The most likely reason is the type of fat. Many keto meal plans lean on butter, cream, cheese, coconut oil, bacon and fatty cuts of meat, which are high in saturated fat. Harvard’s review of the keto diet notes that it often emphasizes saturated fat, which may have adverse effects on LDL.
Keto also cuts out foods that help lower cholesterol, such as oats, beans, lentils and fruit, which are rich in soluble fiber. The Keto-Med researchers linked keto’s lower nutrient intake to avoiding legumes, fruits and whole grains.
How to keep cholesterol in check on keto
- Make unsaturated fats your main fats. Cook with olive or rapeseed (canola) oil, and use avocado, nuts, seeds and oily fish. The NHS guide to lowering cholesterol recommends these over butter, lard, ghee, cream and fatty meat.
- Cut back on the biggest saturated fat sources: butter, cream, cheese, coconut oil and processed meat. Use them for flavor rather than as staples.
- Eat oily fish twice a week, such as salmon, mackerel or sardines. Our guide to healthy fats on keto has more ideas.
- Load up on non-starchy vegetables, nuts and seeds for fiber. Chia and flaxseed are high in fiber and low in net carbs.
- Keep up physical activity. The NHS recommends at least 150 minutes of moderate exercise a week as part of lowering cholesterol.
- Get tested. Ask your doctor about a cholesterol test before starting keto and again after a few months.
Who should be especially careful
People with familial hypercholesterolemia, an inherited condition that causes very high LDL from birth, are on the list of people who should only try keto under medical supervision, according to a 2026 review of keto’s contraindications. If you have a family history of very high cholesterol or early heart attacks, talk to your doctor before starting.
If you already have heart disease, high cholesterol or diabetes, or you take statins or other heart medicines, don’t start keto without talking to your doctor. Never stop or change a cholesterol medicine because of diet changes without medical advice.
Keto vs a Mediterranean-style low-carb approach
If your LDL rises on keto, a less strict approach may suit you better. In the Keto-Med trial, a Mediterranean-style diet that cut added sugar and refined grains but kept legumes, fruit and whole grains improved blood sugar about as much as keto, while LDL fell instead of rising. People also found it easier to keep up. Our beginner’s guide to the Mediterranean diet explains how to start.
A cholesterol-friendly keto day
- Breakfast: eggs scrambled in olive oil with spinach and mushrooms, with half an avocado.
- Lunch: a large salad with canned salmon or sardines, olives, cucumber and an olive oil dressing.
- Snack: a small handful of walnuts, or celery with almond butter.
- Dinner: chicken thighs roasted with zucchini, peppers and broccoli in olive oil.
- Dessert: raspberries with a spoonful of plain Greek yogurt and chia seeds.
That day is low in carbohydrate and high in fat, but most of the fat is unsaturated. Compare it with a day built on bacon, butter coffee, cheese and cream, which can easily exceed the World Health Organization limit of 10% of energy from saturated fat.
Common questions
How long after starting keto should I check my cholesterol?
There’s no single rule. Many doctors suggest a test a few months after a major diet change, so your results reflect your new way of eating. Ask your doctor what’s right for you.
Does the rise in LDL go away?
It varies from person to person, and long-term studies are limited. Don’t assume it will settle without checking. Our guide to whether keto is safe long term covers the evidence.
Are eggs a problem for cholesterol on keto?
For most people, the NHS guidance on lowering cholesterol focuses on cutting saturated fat from foods such as fatty meat, butter, cream and cakes, rather than on eggs. If you have high cholesterol, ask your doctor or dietitian how many eggs suit you.
Before you start
Safety note: A ketogenic diet isn’t safe for everyone. Don’t start one without medical supervision if you have type 1 diabetes, take insulin or other diabetes medicines (especially SGLT2 inhibitors such as empagliflozin or dapagliflozin), take medicine for high blood pressure, have kidney, liver, pancreas or gallbladder disease, are underweight or have had an eating disorder, or are pregnant or breastfeeding. Children should only follow keto as a medical treatment run by a specialist team. A 2026 review of keto’s contraindications lists these and other situations that need care, so talk to your doctor first if any apply to you.
This article is general information, not medical advice. Talk to your doctor or a registered dietitian before making big changes to how you eat, especially if you have a health condition, take regular medication, or are pregnant or breastfeeding.
