Posted on: April 26, 2018 at 9:09 am
Last updated: September 17, 2018 at 2:23 pm

You may have only recently heard about the ketogenic diet, a very high-fat, low-carb diet that’s taking the nutrition world by storm—but believe it or not, the keto diet has been around since the 1920s. The ketogenic diet (or keto, for short) was originally developed by doctors for medicinal use, especially for helping to treat epilepsy, obesity, and metabolic diseases. Today, however, the keto diet is gaining widespread attention for different reasons—people are turning to the diet to lose weight fast and improve overall health.


The ketogenic diet works by forcing the body to use fat as an alternative fuel source once glucose from carbohydrates is no longer available. This fat comes from the diet as well as stored body fat. The ketone bodies that are produced during this process then supply the brain and organs with energy, helping to prevent the fatigue that is typically associated with calorie-restrictive diets.

In order for you to stay in the metabolic state of ketosis and produce ketones, you need to get about 75-80% or more of your daily calories from fat, and just about 5% from carbohydrates. Put differently, carbohydrates are usually limited to less than 20-30 grams per day, while fat is increased substantially.


When the keto diet is followed closely, it can trigger some major health benefits:

  • The keto diet has been shown to be a reliable way to lose weight, even for people who struggle with other diets. This is because ketogenic diets typically reduce hunger and lower overall food intake significantly.
  • The keto diet, reportedly, also offers protection against neurological diseases by reducing inflammation and protecting the brain. It can also enhance mental performance, increase energy levels, help to balance hormones, and kill cravings.

There are some potential drawbacks to the keto diet, however:

  • The keto diet requires you to give up nearly all carbohydrates besides vegetables— which can be much too restrictive for some people.
  • The keto diet can also initially cause some side effects—including headaches, low energy, cravings, and moodiness—that may last 1-2 weeks while the body goes through necessary metabolic changes. (This has been nicknamed “the keto flu”.)
  • Additionally, some health experts believe that the keto diet can have a negative impact on cardiovascular health.

Heart Health and the Keto Diet

According to certain anecdotal reports published online, it appears that not every person will respond favorably to diets that are very low in carbs and high in fat, especially saturated fat from animal sources like meat and dairy products. For example, Dr. Joel Kahn recently reported on Thrive Global that a patient of his who began a ketogenic diet wound up struggling with heart-related problems as a result— including increased total cholesterol, formation of artery calcium deposits, and, in his opinion, a higher risk for atherosclerosis.

Generally speaking, the impact of very high-fat diets on cardiovascular risk factors is still controversial. It’s important to point out that this is only one person’s opinion— and there are plenty of researchers and doctors who believe the ketogenic diet can be safe and beneficial, especially for treating obesity and type 2 diabetes. In fact, some studies have reported a benefit of the keto diet on triglycerides and HDL cholesterol levels. A number of human studies also found evidence that the keto diet is associated with significant reductions in total cholesterol, increases in HDL cholesterol levels, decreases in triglycerides levels, and reductions in LDL cholesterol levels.

It’s important to note that there are many variables to consider in the case of Dr. Kahn’s patient. It’s unclear if the patient was sticking to a whole foods diet that included plenty of vegetables and high-quality animal products (grass-fed, pasture-raised, etc.). We also don’t know how his medical history, stress, lack of sleep, potential nutrient deficiencies, genetics, and intense exercise may have affected his results.

More Experts Raise Concerns About the Ketogenic Diet

Dr. Kim Williams, cardiologist and president of the American College of Cardiology between 2015 and 2016, has strong opinions about the keto diet. “No one should be doing this,” he commented, after reviewing a research study that suggested an association between the keto diet and heart attacks.

Dr. Marcelo Campos of Harvard Vanguard also suggests alternatives to keto: “Instead of engaging in the next popular diet that would last only a few weeks to months (for most people that includes a ketogenic diet), try to embrace change that is sustainable over the long term. A balanced, unprocessed diet, rich in very colorful fruits and vegetables, lean meats, fish, whole grains, nuts, seeds, olive oil, and lots of water seem to have the best evidence for a long, healthier, vibrant life.”

Overall, many factors can influence how beneficial (or not) the ketogenic diet will be. The best results are typically seen in people who eat a good deal of alkalizing foods (mainly vegetables) in addition to meat and fats, practice stress management, and have a regular fitness routine that’s appropriate for their age and overall health.

That being said, this example does illustrate that some people may respond poorly to the ketogenic diet, so it’s important to monitor your progress and make changes if need be. It’s possible that some individuals may be predisposed to developing heart-related conditions that are made worse by the keto diet. Everyone reacts a bit differently to various diets, so finding a personalized diet that helps you feel great and that you can stick with is most important.

The Importance of Eating Well on the Keto Diet

If you’re concerned about how a low-carb, high-fat diet will impact your health, the best thing to do is work with a medical provider who can help monitor your lab results. And if you find that your health makers are moving in the wrong direction, you know it’s time to make some changes.

To get the best results from the ketogenic diet—including weight loss but and improvements in your overall health—you need to focus on eating the right foods. Not all high-fat foods are healthy, and having multiple servings of vegetables each day is critically important for many reasons.

Here’s a guide on the types of healthy foods you should eat while on the keto diet, along with a list of the foods you’ll want to limit or avoid:


  • Plenty of healthy fats (at least 70% of your calorie intake). The best sources include: coconut milk/flakes or coconut oil, MCT oil, real olive oil, grass-fed butter, ghee, and avocado
  • All types of non-starchy vegetables, including broccoli and other cruciferous veggies, all types of leafy greens, asparagus, cucumber, mushrooms, green beans, and zucchini
  • Sprouted nuts and seeds, especially chia seeds, flax seeds, almonds, and walnuts.
  • Organic grass-fed meat and pasture-raised poultry. Organ meats like liver are also beneficial and nutrient-dense
  • Wild-caught fish
  • Cage-free eggs
  • Raw, organic dairy products (ideally fermented), like aged cheeses, butter, or cream
  • Bone broth or collagen/bone broth protein powder
  • Other superfoods like cocoa powder, apple cider vinegar, and sea vegetables


  • Foods made with refined sugars and fructose, which are associated with metabolic syndrome. This includes fruit juices, processed foods with any type of flour of sugar, all desserts, soda, and other drinks high in sugar
  • Foods made with any grains or white/wheat flour, including bread, cereal, pasta, cakes, cookies, etc.
  • Conventional dairy products, especially low-fat and sweetened types.
  • Fruit (even though it’s a whole food, it still provides carbs and sugar which interferes with ketosis)
  • Medium-starchy veggies like sweet peas, carrots, beets and any kind of potatoes, legumes, and beans. Eat only small amounts of nuts and seeds and dairy products like yogurt/kefir, since these do provide some carbs

Following these food guidelines will help to ensure that you achieve the best results possible from the keto diet, while minimizing the potential negative impact on your cardiovascular health.

This fantastic article is written by Dr. Josh Axe. Check out his website or follow him on Facebook for more great information!

Josh Axe
Doctor of Natural Medicine
Doctor of Natural Medicine at Exodus Health Center Dr. Josh Axe, DNM, DC, CNS, is a doctor of natural medicine, clinical nutritionist and author with a passion to help people get well using food as medicine. Dr. Axe is the author of Eat Dirt and Essential Oils: Ancient Medicine , and he's also the founder of , one of the world's top natural health sites that draws more than 11 million visitors each month.

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