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March 22, 2019

Ketogenic Diet – What?

Written by Avance Care registered dietitian Chris Thompson, MS, RDN, LDN

Many diets spark interest in the minds of individuals looking to manage weight, blood sugars, and more. Lately, the ketogenic diet has been garnering a lot of attention. But is it new? And what is it?

Where Did It Come From?

Modern physicians first introduced the ketogenic diet as a treatment for epilepsy in the 1920s¹ and it was widely used until anti-epileptic drugs were introduced two decades later. The ketogenic diet has since returned to the scene. It has been exploding in popularity over the past 15 years and prior with the introduction of Atkins, Paleo, and South Beach diets. These diets are different from an actual ketogenic diet in that a ketogenic diet is even more restricted. Let’s dive in.


What Is the Ketogenic Diet Exactly?

Before we get into what the ketogenic diet is, it’s important to understand how cells obtain and use energy. The body’s preferred source of energy is sugar that comes from carbohydrates. When we eat carbohydrates, we convert them into usable energy in the form of glucose (sugar). Our cells use these sugars when we walk, talk, lift weights, run, or even think. The brain is one of, if not the biggest, consumer of these sugars.

The ketogenic diet relies on a different source of energy, known as ketone bodies. Hence the name ketogenic or keto diet. Ketone bodies are a form of energy that our livers produce from stored fat. While this may seem like a preferred way to lose weight or manage blood sugars, it can be difficult to get our livers to make this type of fuel.

The keto diet requires severe deprivation of carbohydrates in the amounts of less than 20-50 grams per day to force our body into a state of ketosis where ketone bodies are formed and used as energy instead of glucose or sugar. For example, a banana the length of a pencil, ½ cup of cooked oatmeal, 1/3 cup of brown rice, or ½ an ear of corn are each 15 grams of carbohydrates. The ketogenic diet is high in fat, moderate in protein, and very low in carbohydrates. The purpose of this is to shift our metabolism from running on glucose (sugar) to ketone bodies. A 2,000-calorie meal plan may look like 165 grams of fat, 40 grams of carbohydrates, and 75 grams of protein.²


Is It Safe?

Due to the high amounts of fat in the ketogenic diet, large amounts of saturated fat (the type of fat associated with an increased risk for heart disease) are typically consumed from red meats. Additionally, types of proteins, specifically lean proteins or proteins with heart healthy unsaturated fats like salmon and tuna, are not usually distinguished from or emphasized over higher saturated fat animal proteins like bacon and beef. Adding too much red meat may also increase risk for colon cancer.

The diet also restricts major food groups. Vegetables are limited to lower-carbohydrate options like spinach, kale, cauliflower, broccoli, brussels sprouts, garlic, bell peppers, onions, cucumber, celery, mushrooms, and few others. Fruits are another story. As all fruits are rich in carbohydrates, they are limited on the ketogenic diet.


So… Is It Safe?

Are there risks involved? First and foremost, the diet may be high in saturated fat which can increase risk for heart disease. More so, the diet may be incomplete as it is often implemented. It is possible to have a nutrient-dense dietary pattern on a ketogenic plan if individuals focus on choosing lean proteins, heart-healthy fats, and adequate amounts of very low-carbohydrate vegetables; but typical use of the diet is often incomplete. Limiting food groups like grains and most fruits and starchy vegetables may put individuals at risk for certain vitamin and mineral deficiencies commonly found in these foods. The diet can also put a lot of strain on the liver to produce enough ketone bodies for fuel and may worsen existing liver issues. Increasing protein intake may also strain the kidneys, which play a key role in processing protein. The diet may be low in fiber if not enough non-starchy vegetables are consumed and could result in constipation. Fiber also helps keep cholesterol levels within normal ranges and can help lower cholesterol in those with elevated levels. Lastly, many people experience short-term mental symptoms like foggy brain and/or irritability known as the “keto-flu” while the body adapts to using ketones as its primary source of energy. The onset of these symptoms may occur two to seven days after starting the diet, but for many it will go away after following the diet for a few days or weeks. Potential onset and duration of the “keto-flu” varies from person to person.


What Should You Do?

It is important to understand potential risks associated with such a drastic shift in how our bodies get energy and current research is mixed. Short-term studies may show comparable, even improved, results when compared to traditional calorie-restricted diets³ ⁴ but long-term results and implications (greater than two years) are unknown. Lastly, any type of restrictive diet may be expensive, hard to sustain, and it can be difficult to return to a normal diet once goals are achieved. Until more research is available, a balanced diet including whole grains, fruits, vegetables, lean proteins, and heart-healthy fats is recommended for optimal and sustainable health.

There are side-effects and risks associated with this diet. If you are interested in starting the ketogenic diet, talk to your Avance Care physician and registered dietitian. Collaborating with your health care providers can enhance coordination, continuity of care, and provide appropriate monitoring and support.


“Don’t count the days, make the days count”

— Muhammad Ali







Chris is a Registered Dietitian at Avance Care’s Apex and Holly Springs locations. He loves experimenting in the kitchen, staying active, playing and watching sports, spending quality time with his two dogs, and reading Muhammad Ali quotes.

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