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If you’ve read up on the ketogenic diet, you might have some questions — especially about eating so much fat if you have high cholesterol. Can eating piles of cheese and avocado really help you lose weight? And will it be at the expense of your heart health?
We were curious too — if you haven’t noticed, health is kind of our thing — so we looked into what science has to say. The general consensus: Plenty of studies have found the keto diet beneficial for heart health and improving lipid profiles (the amount of fat in your blood).
The only caveat? Many of these studies were short-term (less than a year), so we’re not quite ready to make any long-term health claims.
Remember that it’s best to chat with your healthcare provider before making major diet changes. Knowing your numbers and family history is the best way to ensure you’re choosing the right lifestyle for you, trends be damned!
Here’s what we know so far about the keto-cholesterol connection.
The ketogenic diet is a very low carbohydrate, high fat diet that was developed to help children and adults experiencing epileptic seizures. It’s now used to help people reach a number of health goals, including weight loss.
The diet requires getting roughly 5 to 10 percent of your daily calories from carbohydrates, 15 to 20 percent from protein, and a whopping 70 percent from fat. Severely restricting carbohydrates (your body’s preferred source of fuel) forces your body to burn fat for energy instead.
Research has shown that the keto diet has several health benefits, at least in the short term. Most notably, folks on the diet have experienced significant weight loss, improved blood sugar, and improved cardiovascular health (ding ding ding!).
You ask such tough questions! Let’s just say it’s not not healthy. If you choose the right foods — like better-for-you unsaturated fats, lean proteins, and complex, fiber-filled carbohydrates — then yes, it can be “healthy.”
These foods will help ensure you’re getting important nutrients, but the diet is still super restrictive, meaning you may miss out on other essential nutrients and put yourself at risk for certain deficiencies. Plus, it’s not necessary (or sustainable) long-term for most people.
While there are undoubtedly short-term benefits, including weight loss and improved blood sugar control, the science is lacking as far as long-term health benefits and/or risks associated with following a ketogenic diet.
Cholesterol is a fat-like substance found in your blood. It’s produced by your liver (which means you don’t need to get it from outside sources like food) and is a key player in ensuring that your body functions properly.
You can thank cholesterol for things like hormone production, building tissues and cells, and absorbing fat-soluble vitamins (oh, hey, vitamin D!). Cholesterol can also be found in food — mostly in animal products like meat, fish, eggs, and dairy.
The keto diet has been shown to affect both LDL (“bad”) and HDL (“good”) cholesterol, but studies have been small and short-term with varying results. (Get more info on HDL vs. LDL cholesterol here.)
It’s kind of a toss-up, but science seems to agree that eating nutrient-dense foods while on the keto diet won’t negatively affect your cholesterol levels or heart health.
What does the keto diet do to your cholesterol levels?
The keto diet appears to improve cardiovascular health markers, including (according to certain studies) cholesterol and triglyceride levels.
Research from 2004 suggests that people with obesity and high cholesterol experience greater weight loss and bigger improvements in triglyceride and HDL levels when on a keto diet than on traditional low fat diets.
Fewer studies point to poor outcomes like increased LDL and decreased HDL levels, and those tend to improve over time. The important thing to remember is that the types of foods you eat really matter.
Is it safe to be on the keto diet with high cholesterol?
Bob Harper will be the first to tell you it’s best to talk to your doctor before attempting something like the keto diet.
Some people, particularly those with familial hypercholesterolemia (high cholesterol levels inherited from your fam), kidney disease, and liver disease, are not good candidates for keto because it can often make these conditions worse.
Some may find their bodies can’t handle taking in that much fat on the daily.
Even for otherwise healthy people, a keto diet filled with saturated fats from red meat and full fat dairy that’s also low in fruits and vegetables won’t lead to improved cardiovascular health in the long term and may actually do some damage.
In fact, a 2011 study found that otherwise healthy men had an increased risk of developing type 2 diabetes after eating a low carb diet rich in saturated fat.
What foods are keto-approved?
A keto diet is typically mapped out using some specific calculations to make sure you enter and stay in ketosis (a fat-burning state) and meet your individual needs. Eating more than 5 to 10 percent carbs will usually take ya right out of ketosis.
You’ll be eating mostly:
- red meat
- dairy (cheese, yogurt, milk)
- non-starchy vegetables
For most people, getting 5 to 10 percent of calories from carbs means eating 50 grams or less per day, and it can be as low as 20 grams. For reference, 2 cups of cooked broccoli or 1 1/2 cups of strawberries roughly equals 20 grams of carbs, which is more than the measly 1/2 cup of rice you could eat for the same 20 grams of carbs with hardly any nutrients.
Once you’ve figured out your carb sitch, it’s all fat and protein from there.
Technically you can choose to eat any fats and proteins you’d like, but stick with unsaturated fats and lean proteins — like eggs, fish, seeds, and nuts — to maintain or even improve your health, depending where you’re starting from.
We’ve spent a lot of time talking about cholesterol, LDL vs. HDL, and triglycerides. If you want a deeper understanding of what these fats are, we got you.
What’s the difference between LDL and HDL cholesterol?
Time for a quick bio lesson. Cholesterol needs to travel through your bloodstream to complete its daily tasks, but it can’t move around on its own. To get moving, it partners with protein to form lipoproteins.
Like the autobots and the decepticons, there are two main forms of lipoproteins: low-density lipoproteins (LDL) and high-density lipoproteins (HDL).
LDL (aka “bad cholesterol” — or, in this metaphor, the decepticons) carries cholesterol through your bloodstream, but it can easily get stuck in your arteries, especially if there’s too much floating around (think of it like a traffic jam).
If too much builds up on artery walls, it becomes more difficult for blood and oxygen to flow through.
HDL (aka “good cholesterol”/the autobots) acts like a mop. As it travels, it picks up LDL cholesterol and brings it back to your liver, where it’s promptly disposed of. The more HDL you have, the less LDL is floating around in your bloodstream and the less likely it is to collect on your artery walls.
Keeping these levels skewed in the autobots’ favor is essential, especially when following a keto diet. Exercise, eating nutritious foods, drinking plenty of water, and limiting alcohol can keep the decepticons at bay.
What are triglycerides?
Ready to take your knowledge a step further? Like cholesterol, triglycerides are a type of fat circulating in your blood. But their function is completely different.
Cholesterol actively supports life-sustaining bodily functions, whereas triglycerides are emergency fuel stores created when we eat too much (just keeping it real, folks).
In the cave-dwelling days, this was a huge benefit. People lived during times of feast or famine and needed this stored energy for the days food was less abundant. Nowadays, when almost everyone lives within 5 miles of a superstore, you can see how it’s pretty easy to live that feast life.
But why do triglycerides matter? Because, like LDL cholesterol, triglycerides are smaller particles that can get stuck on artery walls, causing plaque buildup and leaving less space for blood and oxygen to flow to your organs and other vital tissues.
- The keto diet’s long-term effects on cholesterol and cardiovascular health remain unclear.
- Research indicates that keto’s impacts on cholesterol levels and overall health are specific to the individual and depend on eating nutrient-dense foods.
- Before trying the keto diet, talk to your healthcare provider. Have a firm grasp of your health, your numbers (i.e., blood sugar, cholesterol, and other levels determined by blood work), and your family history.
- Once you get the green light, see a registered dietitian to come up with a meal plan that meets your nutrition needs and is keto-approved.