Watch Out for These Side Effects if You’re Following the Keto Diet

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Considering trying the keto diet? You’re not alone. People everywhere are experimenting with this popular weight loss plan, which quickly became 2018’s most trendy and talked-about diet. Before you give it a go, however, there are some things you should know about: namely, these keto diet side effects that can throw your body for a loop and may not be the best for your overall health.

Assortment of High-Fat Foods Like Butter and Cheese That May Contribute to Keto Diet Side Effects |

What is the keto diet?

The keto diet – or ketogenic diet – was originally created to treat epilepsy, a serious seizure condition affecting both children and adults. Its point was to dramatically lower a person’s intake of carbohydrates, thereby triggering certain metabolic reactions in the body.

In actuality, the keto diet prescribes that followers consume 70 to 80 percent fat, 15 to 25 percent protein and five to 15% carbohydrates, depending on the individual and whatever ratio of macronutrients they choose.

The human body is programmed by design to use naturally occurring carbohydrates from whole foods (fruits, vegetables, whole grains, etc.) for energy and metabolic maintenance. It breaks down carbs into glucose, which enter cells to fuel metabolism. Technically, whole foods are optimal because they take longer for the body to break down than “quick sources” of glucose, like refined sugar.

Since the keto diet eliminates carbohydrates, it forces the body to use stored fat (along with some protein) as fuel instead of glucose produced by carbohydrates. This, in turn, leads the body to produce metabolic wastes, known as ketones.

For patients with epilepsy, the production of ketones triggers a set of reactions that change the way the brain works, which can actually diminish and eliminate epilepsy for good. The side effects of the diet in patients with epilepsy can range from kidney issues, malnutrition issues, constipation, headaches and more. This is one reason that anyone with epilepsy who undergoes a ketogenic diet as therapy must be seen by a physician to ensure they receive proper care. 

Why the keto diet is popular: weight loss & more

Today’s popular version of the keto diet differs from the one usually administered in a health clinic setting to treat epilepsy. A day on the keto diet by the general public typically involves eating high-fat, unrefined plant oils, high-fat plant foods, high-fat sources of animal protein, and very small portions of non-starchy vegetables.

One of the most well-known side effects is weight loss (which is why keto is all the rage today). The keto diet leads to quick weight loss because intake of added sugars, refined grains and processed foods high in refined carbohydrates comes to a complete halt. Many people also naturally avoid refined fats (such as vegetable oils high in trans fats) because they aren’t eating processed foods.

(Note: Avoiding these foods is an aspect of the keto diet – or any low-carb diet, for that matter – that shouldn’t be overlooked. It’s one of the leading reasons people lose weight and see benefits on the keto diet—not necessarily by eliminating healthy foods like fruits and vegetables that are higher in carbohydrates).

Common side effects of the keto diet

Despite eliminating unhealthy carbs and refined fats, the keto diet still doesn’t come with a green light for ultimate health.

Remember, ketogenic diets were originally designed to treat epilepsy—not for non-epileptic adults wanting to lose weight. While a keto diet can assist with weight loss, the results are usually short-lived—they go away when the diet is stopped. In addition, there are some health implications – some of which are dangerous – that you should be aware of.

Consider the following keto diet side effects and be sure to talk to your health care provider before beginning.

1. Heart disease

The keto diet is a high-fat diet, including smaller amounts of protein and almost no carbohydrates. Consuming calories mostly from fat is cause for health concern, including heart disease—especially for people with a family history.

Some of the most important foods for preventing and even reversing heart disease are fruits, vegetables and whole grains. These foods are all rich in carbohydrates for the most part, which means those on the keto diet must avoid them. While some keto dieters eat some low-carb produce, whole grains are still prohibited.

Unfortunately, whole grains are among the top foods to improve heart health and help prevent heart disease. High-fat diets have been directly tied to heart disease, especially when fats come from animal-based fats, such as butter, bacon, cheese, meat and even large amounts of high-fat seafood items. In fact, these foods can actually prevent the entrance of glucose into the cells, which is one reason that many people who eat a high-fat diet have Type 2 diabetes and heart disease associated with the disease.

2. Digestion complications

Fat takes longer to digest than any other macronutrient, which means a ketogenic diet may cause digestion complications. High-fat foods sit in the stomach and can take much longer to digest than carbohydrates or protein. High-fat foods have also been directly linked to a decrease in beneficial gut bacteria (which help) digestive issues from occurring.

In fact, constipation is one of the leading side effects of the ketogenic diet, which is why many people have to take fiber supplements on the diet. Instead of taking fiber supplements—which are devoid of natural nutrition—individuals would be better off eating high-fiber plant foods like fruits, vegetables and whole grains that come with heart health benefits, weight loss benefits and that feed good bacteria in the gut, supporting optimal digestive health.

3. Micronutrient deficiencies

Fruits and vegetables are rich in vitamins and minerals that give our bodies the micronutrients they need for optimal health. These micronutrients help us fight disease, improve gut health, and maintain a healthy weight and higher energy levels. Plus, they help support a healthy heart. Because a ketogenic diet eliminates such a large portion of fruits and vegetables (along with all whole grains), intake of these beneficial micronutrients needed for optimal health is dramatically reduced. 

4. Increased heart rate, electrolyte imbalances and dehydration

Many people experience dramatic electrolyte imbalances and dehydration, along with increased heart rate (as the body produces ketones and water weight loss is triggered), within the first few weeks of following the ketogenic diet.

Individuals on the keto diet are often recommended salt tablets, higher amounts of salt or electrolyte drinks to counteract these side effects.

For best health, of course, we’d consume whole foods such as fruits and vegetables that provide plenty of water and naturally occurring electrolytes such as potassium. The nutrients these foods naturally support and regulate electrolyte balance and can decrease the risk of high heart rate that occurs when electrolyte imbalances occur.

5. A disordered relationship with food

The ketogenic diet can trigger negative relationships with food. It can change the way a person feels about natural, whole foods, leading to disordered eating. Fruits, vegetables and whole grains should never be seen as “bad” foods, nor should nutritious whole foods that are high in natural fats (like nuts, seeds and avocados) be regarded as “bad.”

Of course, not everyone who follows the keto diet will develop an eating disorder. It’s just something to keep in mind because the diet is extreme and especially might affect someone who is prone to a disordered relationship with food.

Other risks to be aware of

Other risks of the ketogenic diet include organ damage (especially to the kidneys), along with heart issues, since many people following the diet lose natural protein stores which can affect the heart.

Some women also experience menstrual issues, as a low-carb diet can trigger amenorrhea (the cessation of mensturation). Other risks associated include thyroid issues, adrenal imbalances, and more.

The bottom line

Be sure to do your research before starting a ketogenic diet, and always check with your primary care physician or a licensed naturopath before beginning any diet that eliminates entire food groups.

It’s also important to remember that just because one diet works for someone, doesn’t mean it will naturally be the right one for you or be the one you should follow long term!