Basket of eggs, example of food eaten for keto diet

Understanding the keto diet and cholesterol

Medically reviewed on June 27, 2022 by Jordan Stachel, M.S., RDN, CPT. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

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Diet trends come and go. Some are supported by questionable science that can lead to disordered eating while also doing very little for your actual health, but many more can make a meaningful change with the right precautions.

The keto diet is one of the most popular current diets, offering a fairly sustainable eating plan that allows people to better manage their weight, body mass index, and cholesterol and even lower their risk of heart disease. While you should consult your doctor before trying the keto diet or making any other significant changes to your diet, there are certainly benefits associated with it. Here are some facts about the keto diet and how it might help you.

What Is the Keto Diet?

Low carbohydrate, high protein eating plans are fairly popular and not particularly new. The Atkins diet, which emphasized protein over everything else, enjoyed a fairly prominent time in the sun, while the Paleo and South Beach diets offered similar but slightly altered diet plans.

These types of diets that focus on low carbohydrate intake and high proteins are sometimes broadly referred to as ketogenic (or simply “keto”) diets, but a true ketogenic diet is slightly different. It still emphasizes a low carb intake, but the keto diet specifically centers on fat. With keto, up to 90 percent of your daily calories are meant to come from fats, making it an extremely high fat diet.

As you can imagine, this is not a diet that should be taken lightly. Keto diets are primarily used in neurological medicine, and they have been shown to help reduce epileptic seizures in children. They may help with weight loss, weight management, susceptibility to cardiovascular disease, and cholesterol.

Understanding the Macronutrients

Macronutrients are the three main components of any diet: protein, carbohydrates, and fats. You need all three to keep your cells, tissues, and organs functioning properly. All three also provide your body with fuel in the form of calories, and they each serve their own specific purposes in the body. Protein, for example, gets broken down into amino acids that build and repair tissues and allow your body to grow.

Of the three main macronutrients, carbohydrates tend to get most of the blame for body weight gain and ill health. Much of this comes from just how your body tends to make use of carbohydrates. Carbs are your body’s preferred fuel source. It’s easier for your body to break down carbs into immediately usable energy than the other two macronutrients. Carbohydrates get broken down into glucose, a simple sugar that can be an immediate source of energy for all of your body’s cells. However, if you don’t use up all of that glucose, it gets stored for future use in the form of body fat.

Dietary fat (the macronutrient) is another source of energy, however, it can have an even worse reputation than carbohydrates. It’s easy to assume that eating fat equates to more body fat. While certain fats can contribute to weight gain, many fats are good for you and essential to your health. Fat is necessary for basic cellular function, hormone production, insulation, and protection for your organs.

Macronutrients and Ketosis

Fat is more calorically dense than carbohydrates. Fats contain about 9 kcal per gram, while carbohydrates contain about 4 kcal per gram. However, carbohydrates are your body’s first source of energy. Cells will only begin to pull energy from fat stores when you are out of the glucose that comes from carbs.

The keto diet forces your body to turn to fat as its main source of fuel, a state known as ketosis. As your glucose stores wane, your cells will use molecules known as ketone bodies as a source of energy. Ketone bodies are a type of fuel produced by the liver from stored fats.

Burning stored fat seems like an ideal way to manage weight and lose some excess pounds, but actually reaching a state of ketosis and getting the liver to create ketone bodies is harder than you think. The main requirement is a massive deprivation of carbohydrates. Your exact metabolism will vary, but that generally means fewer than 20 to 50 grams of carbohydrates per day. To give you an idea, a single medium banana contains about 27 grams of carbs.

Even if you do reach those low carb levels, it is not an instant process. It can take a few days for your body to reach a state of ketosis. The amount of protein that you consume can also interfere with the ketosis process.

What You Eat on the Keto Diet

The exact ratio of fats, proteins, and carbs will vary based on your personal needs, but the main focus on the keto diet is fats, which often means eating fats for every meal. That can look something like 40 grams of carbs, 75 grams of protein, and 165 grams of fat (assuming an average 2,000-calorie daily diet).

The keto diet mainly encourages high amounts of saturated fats, including:

  • Butter
  • Lard
  • Cocoa butter
  • Plant oils, like coconut and palm oil

The diet also allows for some healthy sources of unsaturated fats, including:

  • Nuts, like almonds and walnuts
  • Seeds
  • Tofu
  • Avocados
  • Olive oil

The main restriction is trans fats, which generally shouldn’t exist in any diet, keto or not. Trans fats typically come from hydrogenated oils, which involves adding hydrogen molecules to unsaturated fats. Unlike other fats, trans fats actually raise your “bad” cholesterol while reducing your “good” cholesterol.

Along with fats, the keto diet includes some protein. There isn’t much discrimination here between leaner sources of protein, like poultry and fish, or other sources of protein that tend to be high in saturated fats. This generally includes beef, bacon, and pork.

Because the Keto diet is a low carbohydrate diet, carbs tend to be minimized completely, but where does that leave fruits and vegetables? Fruits tend to be high in carbs (though that also tends to be balanced out by high fiber content). Keto diets generally allow for small portions of certain fruits, like berries. Vegetables, also rich in carbs and fiber, are limited to leafy greens, like kale and spinach, along with:

  • Asparagus
  • Bell peppers
  • Broccoli
  • Brussels sprouts
  • Cauliflower
  • Celery
  • Cucumbers
  • Garlic
  • Mushrooms
  • Onions
  • Summer squash

How to Lower Cholesterol on Keto

One of the biggest concerns with low-carb diets of all kinds is cholesterol. Most research shows that these types of diets can result in elevated LDL (“bad”) cholesterol while reducing HDL (“good”) cholesterol — and keto diets aren’t an exception. If you already have high cholesterol, you may want to reconsider a keto diet. Better yet, you may want to try out a diet with foods to lower triglycerides.

For most healthy people with regular triglyceride levels, these changes are mostly considered modest and shouldn’t have a significant detrimental impact on your health. However, to play it extra safe, consider consuming more unsaturated fat than saturated fat, especially if you’re concerned with improving your heart health. You may also want to increase your intake of non-starchy, fiber-rich foods that are low on the GI index.

The keto diet is not for everyone, and before you proceed with any significant diet changes, you should consult your doctor to make sure you can go about it safely. A good way to ensure your health on the keto diet is by monitoring your lipid and cholesterol levels regularly. Everlywell offers a convenient at-home lipid and cholesterol test. With a finger prick sample collection process, you can receive accurate test results that show your total cholesterol levels, HDL cholesterol levels, calculated LDL cholesterol levels, and triglyceride measurements. You can then review these results digitally and gain some useful insights from physicians.

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4. Trans fat is double trouble for heart health. Mayo Clinic. URL. Accessed June 27, 2022.

5. Does the keto diet affect cholesterol? Medical News Today. URL. Accessed June 27, 2022.

6. What Happens to Your Cholesterol When You Go on a Keto Diet? Everyday Health. URL. Accessed June 27, 2022.

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