Keto Diet: Is it Healthy or Dangerous?

keto diet

Pretty much everyone has heard of or maybe even tried a fad diet. You’ve probably heard of Atkins, Paleo, and Whole30 and probably many, many more. The list of diets goes on and on. The latest trendy diet is a Ketogenic diet, also known as the Keto diet. Is this diet a dangerous form of food deprivation, or a healthy way of eating for all of us to embrace?

Here to help us answer that question and more, is Bridget Shea, RD, a registered dietitian at the University of Vermont Medical Center.

First things first, what is the Keto diet?

The Ketogenic diet is a very low carbohydrate, high fat, and moderate protein diet. It’s different from other low carbohydrate diets like Atkins or South Beach. Those diets are high in protein and recommend a more moderate fat intake. In the Ketogenic diet, fat intake is in the range of 80 percent of total calories. Compare that to the Mediterranean diet, universally known as one of the healthiest in the world. It is made up of about 35 percent of calories from fat and considered on the high-fat side.

The diet was used for many years to treat specific conditions, including diabetes in the 19th century. In the 1920s, it started to be used a treatment for epilepsy in children who did not first respond to medications. It’s believed that the presence of the ketones in the brain impacts neurons and reduces seizure activity. The diet has been researched and used in physician-monitored settings to treat Alzheimer’s disease, cancer, diabetes, MS, and polycystic ovary syndrome.

What is a ketone?

A ketone body is produced through the oxidation of stored fat. When you are on the Keto diet, it causes the body to switch its primary fuel source from carbohydrates to an alternative fuel known as a ketone body. The switch happens in a few different ways. It occurs naturally in a state of fasting, or after a few days of being on a very low carbohydrate, high-fat diet.

When the change from the use of carbohydrate to the use of fat is achieved metabolically, it means that the body is in ketosis. That is, the body uses ketone bodies for fuel over the normal preferred fuel, which is glucose or sugar (the basic building block of all carbohydrates). The body’s ability to do this is important because it provides the body with fuels in the case of starvation. It’s a lesser of two evils situation, where starvation would be the worse evil and using ketones is the lesser; it’s our backup.

What does the typical daily diet look like?

The diet is really high in fat, generally 70 to 80 percent fat, and only about 5 percent carbohydrates. That equates to less than 50 grams or carbohydrate per day for most people. That means a typical person consuming a 2000-calorie-per-day diet on the Keto diet would have the amount of carbohydrate in one to two pieces of fruit for the whole day.

People on the diet eat meat, fatty fish or other seafood, eggs, non-starchy vegetables, nuts and seeds, nut butters, avocados, ghee, and lard. Coconut oil is common and some cream or full-fat dairy. Any dairy with lactose, like yogurt, is difficult to fit in due to the diet’s carbohydrate restrictions. Aged cheeses are often included in the diet.

To keep the body in ketosis, meats and fish have to be higher fat, like salmon. Some people add butter or oils to meats for added fat. That’s because too much protein can actually prevent ketosis from happening. The body can make glucose from the building blocks of proteins, the amino acids. If you eat too much protein on the diet, you won’t be in ketosis anymore. That’s why the diet is lower in protein than say the Atkins diet.

Some of those things you mentioned sound like healthy foods. Is this a healthy diet, is it safe?

It’s really hard to say with certainty that the diet is safe because it hasn’t been studied vigorously. We don’t know if it’s safe for people with chronic health conditions. There are some uncomfortable side effects of a very low carbohydrate diet: fatigue, depressed mood, irritability, leg cramps, and headaches. Some people refer to it as brain fog or the Keto flu.

These may subside over time, but for some people, the side effects are more persistent. Constipation is common because the diet is so low in fiber. We find fiber in legumes, grains, and starchy vegetables – all carbohydrates.

There’s also the potential for nutritional deficiencies if people aren’t careful. You may miss out on B vitamins and essential minerals like magnesium and potassium. Often, supplementation is necessary to keep the body healthy.

Another thing to keep in mind is the effect on heart health. One study of children on the diet for six months found that their blood levels of cholesterol and triglycerides increased. This is something to keep in mind if heart disease or cardiovascular conditions run in your family. Research also shows that the Ketogenic diet may increase levels of a stress hormone called cortisol, which is implicated in cardiovascular disease.

I recommend that anyone, and especially those on medications or with a chronic condition, works with a registered dietitian if they want to try the Keto diet. All that being said, I think healthy people who are careful about their food choices, choose healthy fats and vegetables, and meet their micronutrient needs, are safe on the diet in the short-term. In the long-term, we’re not so sure.

Why do you think this diet is so popular?

Fad diets often produce rapid results. With a very low carbohydrate diet, there’s also a quick loss of water weight when you start it. Seeing that initial weight loss motivates and encourages people.

I think the rapid results and the exciting newness of the diet is one thing that makes the diet popular. There’s a big media presence with this diet right now. I think the hype factor that comes along with hearing about it, seeing it, and reading it in the news, magazines, and social media makes the diet exciting and intriguing.

Another thing with a low carbohydrate diet, especially those that are high in fat, is that they can have an appeal because they’re very satiating and filling. People often feel less hungry and that’s obviously and important piece of a diet. Feeling hungry can be a problem when you’re trying to lose weight.

What do you advise people do instead of going on a fad diet?

It’s always my goal to support patients in whatever they chose, as long as I think it’s healthy and makes sense for them. I think it’s important first to provide education if it’s necessary for people on any diet they want to do.

Whenever I’m working with someone I look at what medications they are on, current health conditions, and medical history. The most important thing for me is making a plan that is going to be the healthiest for the patient and align with their goals. The plan needs to be both what they want to do and what they’re excited to do.

I think most people who I work with have attempted weight loss before and already know a little bit about themselves and what may work or what doesn’t work. I use that as a jumping off point. We think about past successes and past struggles. We talk about why those happened. Then we do some food journaling or reflect on the current diet. I always talk to someone about why they’re choosing to do something that’s a little bit more restrictive. It’s likely there’s a reason for it. I explore that with my patients.

The truth is that for me and for most of the people with whom I work, focusing on one or a few small things, and building over time is a method that is less exciting but leads to more gradual results. It can be a more reasonable and enjoyable approach in the long-term than doing something a lot more restrictive.



 Stay Informed

Sign up to receive the latest stories, information and guidance from our experts on a wide variety of health topics.