Is Keto Bad for Your Heart?   

Is Keto Bad for Your Heart?

Is Keto Bad for Your Heart?

July 12, 2019

Clinical Contributors to this story:
Renee M. Dougherty, D.O.
Jacqueline Hollywood, M.D.

By Brianna McCabe

It may only be four letters, but it is one trending diet program: keto.

As the most Googled diet in 2018, keto—short for ketogenic—has been adopted by celebrities such as Halle Berry, Kourtney Kardashian and Lebron James and has since gained traction on social media.

Now if your Instagram feed looks anything like mine, I’m sure you can’t go a day without scrolling past a picture of some kind of bacon-wrapped meat stuffed with cheeses accompanied by the hashtag #ketofriendly. With each post, though, my brain always ponders:

  • What is the science behind keto?
  • Is it really that healthy?
  • So, you’re saying I can eat an entire block of cheese for dinner?
  • Isn’t all of this fat a cardiologist’s nightmare?

Two Hackensack Meridian Health Medical Group physicians help to digest this fat-packed diet.

What makes the keto diet different?

All humans require three main macronutrients: carbohydrates, lipids (fats) and proteins. It is generally recommended that the standard American consumes 45-65% of calories from carbohydrates, 20-25% from fats and 10-15% from proteins.

“The keto diet, though, significantly slashes this percentage of carbohydrates while boosting fats,” explains Renee Dougherty, D.O., board certified in internal medicine. Instead, a person might consume 5% of calories from carbohydrates, 75% from fats and 20% from proteins—though there are some individuals who might take a more aggressive approach and increase fat consumption to 90% and shift the remaining 10% accordingly, notes Dr. Dougherty.

Keto Food Portions Infographic

Is too much fat bad for the body?

“If you remember back in the ‘90s, the Atkins diet was all the craze,” recalls Jacqueline Hollywood, M.D., board certified in cardiology and nuclear cardiology. “This is the low-carb Atkins diet, but with a twist.”

According to Dr. Hollywood, who has tried the keto diet in the past and noticed temporary weight loss, the Atkins diet encourages people to focus on fats—but bad fats. Keto, on the other hand, sometimes encourages much ‘cleaner’ and ‘leaner’ fats depending on the individual’s take on it, she adds.

What are the different types of fats?

“Not all fats are created equal,” advises Dr. Dougherty. Fats are broken down into three main categories: unsaturated (or “good”) fats, saturated fats and trans fats.

“A clean keto diet incorporates more of a Mediterranean diet filled with unsaturated fats, such as vegetable oils, nuts and seeds and some fish,” says Dr. Hollywood.

There are two main types of unsaturated fats: monounsaturated fats, which help lower cholesterol and blood sugar (found in foods such as avocadoes and olive oil), and polyunsaturated fats, which are necessary for proper body functioning (found in foods such as salmon and tuna).

Conversely, saturated fats are found in red meats and dairy products, such as butters and cheeses. “A diet high in these bad fats, like the ‘dirty’ keto, can increase cholesterol and ultimately lead to heart disease,” says Dr. Hollywood. “I’ve stumbled on blog articles discussing how people eat salami, pork rinds and cheeses and have lost weight through ketosis—but this is extremely detrimental to health in the long-run.”

Then there’s trans fats, which are found in processed snacks and baked goods, adds Dr. Hollywood.

Keto Types of Fat Infographic

An increase in fats—though both Dr. Dougherty and Dr. Hollywood agree should be mostly “good”—and decrease in carbohydrates puts your body into a metabolic state of ketosis.

What is the science behind ketosis?

According to Dr. Dougherty, this process—which can take several days—occurs when the body burns off fats instead of carbohydrates. “The liver will produce ketone bodies from stored fats which essentially acts as an alternative energy source,” she says.

So what foods should I eat?

Some cleaner keto-friendly food options include:

  • Eggs
  • Lean poultry and fish
  • Nuts and seeds
  • Nut butters such as peanut, almond and cashew
  • Healthy fats from coconut oil, olive oil and avocado oil
  • Avocados
  • Non-starchy vegetables including broccoli, tomatoes, mushrooms and peppers

Keto-friendly foods that you can eat, but in moderation, include:

  • Red meats
  • High-fat dairy products including cream cheese and sour cream

And what foods should I avoid?

Foods you cannot eat on the keto diet include:

  • Fruit
  • Grains and starches including rice, oats, corn, quinoa and wheat
  • Root vegetables such as potatoes, carrots and yams
  • Grain products such as cereal, bread and pasta
  • Legumes such as black beans, kidney beans, pinto beans and chickpeas
  • Low-fat dairy

Being that there is such an emphasis on fat, is this diet heart healthy?

Because the diet relies heavily on fat consumption, there may be an increased risk in cardiovascular disease for those consuming large amounts of saturated and trans fat, notes Dr. Dougherty.

However, with an emphasis on “good” fats, Dr. Hollywood says that a clean keto diet in the short-term can jumpstart a diet program—which can ultimately reduce risk factors of heart disease.

“When you pull carbs and sugars from your diet, you end up pulling a lot of water weight which results in weight loss,” shares Dr. Hollywood. “Weight loss can lead to improvements in blood pressure, cholesterol and lowering the risk of diabetes. All of these modifiable factors interconnect, which can help boost your heart health.”

Are there potential risks associated with the keto diet?

Individuals following a keto diet tend to avoid certain fruits and vegetables, as they are generally high in carbohydrates. “Therefore certain nutritional deficiencies may be seen,” says Dr. Dougherty.

Should any individuals chat with a doctor before trying to follow a keto diet?

Any patient with a history of heart disease and/or is on medications needs to discuss any diet plans with his or her physician(s), says Dr. Hollywood, as a drastic change in diet may affect the way the medication supports the body.

Does keto work for weight loss?

Dr. Hollywood says that she did notice weight loss while following the diet, but once she started to reincorporate carbs, she gained the weight back.

“I’d encourage those following a keto diet to consult his or her primary care doctor or nutritionist for a transition plan to sustain this weight loss and welcome back proteins and carbs,” she recommends.

However, Dr. Hollywood warns that it is important to be mindful of these ‘extreme’ diet programs, like an aggressive carb-conscious keto. “The ‘all or nothing’ phenomenon I’ve found is not that practical and not that sustainable—and individuals can develop unhealthy relationships with food,” she says.

What kind of relationship should you have with food?

“An individual’s goal should instead be embracing a lifestyle change instead of a diet, which is more sustainable over a long period of time,” expresses Dr. Dougherty. A well-balanced diet, which is high in vegetables and lean meats and low in processed foods, in addition to portion control and daily physical activity has more evidence for success, she adds.

Next Steps And Resources


The material provided through HealthU is intended to be used as general information only and should not replace the advice of your physician. Always consult your physician for individual care.


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