Keto Diet Dangers You Need to Know About

by Marixie Ann Obsioma, MT, undergrad MD on July 13, 2024
Last updated on July 13, 2024

Despite all the fancy gadgets and breakthroughs in medicine, carrying extra weight remains a major health hazard. This condition frequently opens the door to frightening concerns, including soaring blood pressure, cardiovascular troubles, and diabetes. Furthermore, indulging in too much fast food and spending the day lounging around can cause unnecessary weight gain.

Keto Diet Dangers You Need to Know About

A properly-oriented dietary regimen can tackle weight gain and help with obesity. One of the most popular weight loss diets that offer rapid results is the high-fat and low-carb ketogenic diet. Keto eating has gained quite the momentum. With celebrities like Lebron James, Gwyneth Paltrow, and the Kardashians buying in, it’s no wonder why.

In fact, keto and high-fat diets had the biggest adoption increase in the United States from 2018 to 2019. The number of Americans that stuck to these diets went up from 3% of respondents in 2018 to 6% in 2019. But, even if a diet like this offers a ton of promises, it’s still important to talk about the risks. (1)

This is a very difficult and strict eating habit to maintain. And for many, it can prove a real challenge. While low carb diets offer a lot of advantages, one must be well aware of the possible keto dangers too. Here is a detailed analysis of what this diet can bring to your table.

What Is a Keto Diet?

Before we talk about the risks, it’s vital to cover the basics. The keto diet mainly consists of very low carbohydrates, a moderate amount of protein, and high fats. It’s the go-to choice for those looking to curb the extra pounds. It focuses on 2,000 kcal/day. The dietary macronutrients are divided into roughly: (2)

  • 55% – 60% fat
  • 5% – 10% carbohydrates
  • 30% – 35% protein

The goal is simple – put the body into ketosis. This is a process that occurs when the system isn’t getting a sufficient amount of carbs to use for energy. Rather, it focuses on burning fat to make things, known as ketones. These ketones become the necessary fuel.

When in ketosis, it is easier to feel less hungry and keep the muscle when burning fat. Some reports indicate that keto has a number of advantages. Other than effective weight loss, the keto diet benefits can be seen in the improvements of insulin sensitivity and abnormally high insulin levels. (3)

What Are the Negatives of a Keto Diet?

Keto has plenty of risks, stated Harvard Health. When you are considering a fad diet, it’s crucial to take a look at both its advantages and disadvantages to know what you are getting yourself into. Talk to a primary care physician before starting this diet. (4)

Even if this dietary regimen can offer great weight reduction and kept blood sugar control and blood sugar in check, it’s just a quick fix. Not a long-term solution. Many people who did lose weight, often regained it. Some even gained more than they lost. There are also other keto diet risks to consider. The keto diet may cause the following: (5)

1. Flu-Like Symptoms At the Start of a Ketogenic Diet

Can keto make you sick? A commonly reported keto side effect is the “keto flu”. This is a cluster of symptoms that happen in some people in the first couple of weeks after starting their ketogenic diet. The typical symptoms include: (6)

  • Dizziness
  • Nausea
  • Exhaustion
  • Headaches
  • Lack of energy
  • Gastrointestinal problems
  • Brain fog
  • Changes in heartbeat
  • Feeling faint

In most of those affected, the symptoms reach their peak at the first week and dwindle in 4 weeks. Although the severity of the symptoms will vary, they can still be a difficult hurdle to overcome. Considering the current COVID era, anything that looks or feels like the flu can be a real problem.

So, what causes the keto-flu? The strict carb intake (less than 50g/day) can come as a shock to the body. As the system uses all of its carb stores, it starts using fat and ketones to find the necessary fuel. This shock could lead to flu-like symptoms.

Constipation, exhaustion, and nausea could also occur due to electrolyte imbalance and lack of hydration. This happens when the system is adjusting to ketosis. Although most of those affected with the keto flu get better in a couple of days or weeks, it is in your best interest to keep an eye on the symptoms.

Try to drink plenty of water and eat foods packed with electrolytes, potassium, and sodium. Give your body all the energy it needs while supplying it with the necessary nutrients. (7)

2. Possible Risk of Nutrient Deficiencies

It’s easy to stop paying attention to the food you eat when on keto. If you are not munching on a wide variety of grains, fruits, and veggies, you could be prone to nutrient deficiencies. Want to know what nutrients are lacking in the keto diet?

Vitamins C and B, phosphorus, magnesium, and selenium are some of the most overlooked nutrients. To be healthy, you need to establish a healthy relationship with food. If you can’t mitigate the keto risks by yourself, consider talking to a dietitian, nutritionist, or doctor. They can set you on the right track.

3. Low Blood Sugar

2020 reports show that keto can control fasting blood glucose, decrease BMI, and body weight. It can also improve lipid metabolism, which is why it could be used as a part of the integrated management of type 2 diabetes. (8)

But, those with type 1 diabetes could be prone to episodes of hypoglycemia (plummeting blood sugar). This health issue is also accompanied by sweating, exhaustion, shakiness, and confusion. If you are using insulin medication, you should talk to a doctor first.

4. Can Stress the Kidneys

When thinking about keto diet side effects, it’s critical to talk about the kidneys. Consuming plenty of animal foods on a ketogenic diet could cause more acidic urine and make the kidneys susceptible to kidney stones. More calcium is being excreted in the urine, which puts a strain on the kidneys.

Plus, patients with chronic kidney disease (CKD) should avoid this diet. Since the kidneys are weakened, they may have trouble removing the acid buildup in the blood, which can happen when consuming a lot of animal foods. As a result, the diet can add more fuel to the fire for those with CKD. (9)

5. May Trigger Negative Effects on Gut Health

Because of the carb restriction, some people have trouble meeting their daily fiber needs. Besides, the foods packed with fiber are often high-carb fruits, beans, starchy veggies, and whole grains. When you don’t supply the body with all the fiber it needs, that’s when you can develop digestive problems and constipation.

A 10-year study evaluated the impact of the keto diet on gut health. 48 children with epilepsy received keto diets to keep their condition in check. Data shows that this diet curbs the frequency of seizures in some patients with drug-resistant epilepsy. (10)

This is why it can be a worthwhile approach to managing the condition. During the study, the most common keto side effect was constipation recorded in 65% of participants. So, why does keto cause constipation? (11)

When in ketosis, the system is burning fat rather than glucose to get a sufficient amount of energy. The gastrointestinal (GI) tract reacts to the lack of carbs. Constipation makes you have 3 or fewer bowel movements on a weekly basis. To keep this problem at bay, drink more water and consume fiber-rich foods, like avocado, pecans, almonds, etc.

6. Can Harm Bone Health

Strong bones and muscles can protect the body against injuries. They improve our coordination and balance. As a person gets older, it’s crucial to keep the bones in great shape. According to a 2020 report, bone maintenance deteriorated after a short time on a strict ketogenic diet.

The research involved 28 endurance athletes. The volunteers consumed a high-fat, low-carb, or keto diet due to its potential performance benefits. But, sticking to this diet for the long term can deplete bone strength and bone mineral density. (12)

7. Can Mess With the Menstrual Cycle

Women need both nutrients and calories to function normally and have a regular period. When they deprive the body of the nutrients it requires, then it’s normal to experience problems with menstruation. With keto, women are cutting calories, and cutting too much causes cycle irregularities.

These irregularities could be traced to hormone changes. To have a normal menstrual cycle, the female body must release hormones from the brain. Any stressor, whether that is mental unrest, physical activity, or diet can disrupt their hormonal systems. Of course, the diet is not the only thing to blame.

Missed menses could also be a clear indicator of a bigger health problem. Such as PCOS (polycystic ovary syndrome) and genetic abnormalities. If you previously had a normal period but started experiencing irregularities the moment you went on keto, then talk to your doctor. They may advise you to try a different dietary regimen. (13)

Who Should Not Do Keto?

People want to know “is the keto diet safe for diabetics”. Experts suggest that individuals with type 2 diabetes can use keto meals to get fit and decrease their blood sugar levels. Eating keto for a year with type 2 diabetes lowers the A1C. The target A1C for a type 2 diabetic is between 7% to 8%. (14)

But, for someone with type 1 diabetes, keto isn’t a good choice. Even if ketogenic diets can boost glycemic variability and improve hemoglobin A1C, there are still key safety concerns such as diabetic ketoacidosis, hypoglycemia, and dyslipidemia. (15)

Achieving ketosis with type 1 diabetes can cause problems. That’s because type 1 diabetics lack insulin. So, they can’t metabolize ketones the same way a healthy body would. It’s in your best interest to avoid keto with type 1 diabetes. (16)

Keto also isn’t recommended to people with pancreatic ailments or pre-existing liver problems. Including those who recently had their gallbladder removed. Experts suggest that nursing and pregnant women, as well as those prone to heart disease, refrain from using the ketogenic diet. This is a very strict dietary regimen, which for nursing women can prove difficult and lead to nutrient deficiencies.

How Long Should You Do Keto For?

How long is keto safe? This is a question that often pops up. Keto in healthy individuals can be safe when done properly. But, when you stick to this diet for too long, you can deplete the body of key nutrients. Ideally, you should follow it for 3 to 6 months. But, some people prefer to cycle in and out for 1 year.

The keto diet side effects long-term might predispose people to fatty liver, kidney stones, or low protein levels in the blood. Also, the symptoms of mineral and vitamin deficiencies can be mild to severe. Talk to a registered dietitian to know how long you should do keto.

What to Do after Keto Diet Side Effects?

Once you’ve completed your keto journey, it’s time to do a smooth transition. That means quitting keto and avoiding weight gain. After the severe carb restriction, you will need to start implementing carbohydrates carefully. It’s best to focus on consuming carbs packed with fiber and protein.

Sprouted bread, bean-based pasta, and crackers with seeds are great options to start with. Even adding a couple of more avocados and cashews will do the trick. Yes, you will naturally pile a few pounds after eating more carbs. But, if you munch on healthy, whole carbs, you won’t notice a massive spike in weight gain or blood sugar.

Now that you are quitting keto, you may be tempted to indulge foods high in saturated fat or get a few sugary treats. But, once you trade the keto-fat meals for sugary sweets, that’s when all your weight loss efforts can go down the drain. That’s because sugar can be addictive.

What you want to do instead is to pick treats that don’t have over 4g of added sugar. Incorporating good, healthy habits can set you on the right path. Whenever you feel hungry or thirsty, supply the body with the necessary nutrients, minerals, and fluids it needs.

Opt for balanced meals and healthy snacks. For example, have a pesto chicken with some broccoli or rice, or a stir-fry salmon. They are rich in fat, protein, and carbohydrates. Whereas greek yogurt with some berries or dark chocolate and almonds can make for worthwhile snacks.

Final Thoughts

The keto diet has a plethora of benefits. It is mainly used to support weight loss, heart health, and reduce seizures. But because of how strict it is, keto does come with adverse reactions. Keto short-term adverse events include the keto flu, which comes with dizziness, exhaustion, and nausea.

The short-term side effects tend to dissipate in a couple of days to a few weeks. In the long run, keto can make a person susceptible to mineral and vitamin deficiencies. This could get in the way of a woman’s menstrual cycle and throw the body off course.

To prepare the body for the road ahead, it’s best to talk to a specialist. Some individuals with chronic ailments and kidney problems will have to avoid ketogenic diets. If you are having any side effects that affect your day-to-day life, then talk to a doctor.

You may be doing something wrong, or the body needs a different diet. A healthcare expert can advise you on which dietary regimen to follow. Including all the risks and benefits that come with it.


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