Food & Nutrition Science

What are the Pros and Cons of the Keto Diet?

Few eating trends have captivated popular attention in recent years as much as the ketogenic diet. Previously, we’ve discussed the diet’s historic start as a treatment for epilepsy and disclosed what it takes to follow it correctly.

But is the ketogenic diet worth following? Like all strict eating patterns, there are some serious pros and cons to weigh before beginning. By the end of this article, you’ll be one step closer to understanding whether going keto is right for you.

Quick Keto Diet Overview

The ketogenic diet is an eating pattern where you power your body on fat, rather than on carbohydrates. A standard ketogenic diet consists of 75% fat, 20% protein, and 5% carbohydrates, though there is some room for modification to meet your personal goals. If you eat 2,000 calories per day, this breaks down to about 167 grams of fat, 100 grams of protein, and 25 grams or fewer of carbohydrates.

The typical American diet looks very different to the keto diet. It is composed of about 35% fat, 15% protein, and 50% carbohydrates. The interest in alternative eating patterns has risen after large bodies of research attribute several chronic diseases to the Western eating pattern.

Champions of the keto diet argue that the solution to many of the health issues that arise from poor dietary patterns is changing the way your body fuels itself by providing most calories in the form of fat instead of carbohydrates.

By minimizing your carbohydrate intake and consuming healthy fats instead, the ketogenic diet puts your body into ketosis. This is a metabolic state where the liver converts fats into acids called ketone bodies that it uses for fuel. This process simulates fasting conditions to switch up your energy supply. Naturally, there are some significant side effects from this process; some positive and others less so.

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Pros and Cons of Keto Diet

What will the ketogenic diet do to your body? Below are some of the diet’s most commonly reported benefits and side effects.


There’s a reason why the ketogenic is so popular today; it has been shown to result in several improvements in your health and body composition. Here are a few of the most-researched benefits.

Can Help You Lose Weight

One of the most popular reasons people follow the keto diet is because it helps you lose weight and keep it off in the long term when compared to low fat diets.

Research reveals that the diet significantly impacts the amount of body fat you metabolize for energy and following a diet based around high-fat foods tends to boost satiety (help you feel fuller for longer) so that you want to snack less during the day. This keeps calorie counts under control, which can lead to weight loss and an overall change in your body composition.

May Improve Cognitive Functioning

The ketogenic diet has long been understood to affect brain functioning. The high-fat content in the diet helps reduce inflammation that triggers nerve pain in the brain, and research shows that overweight patients who go on the diet experience fewer migraines than they did previously.

Studies are also speculative that the diet can reduce the symptoms or hinder the development of neurological diseases like Alzheimer’s and Parkinson’s, and initial studies suggest that the keto diet may help to regulate ADHD symptoms.

Further evidence shows that powering the brain on ketones can improve the outcome after traumatic brain injuries in young populations, though most research today has only included animal models.

May Slow Various Cancers

Evidence shows that following a keto diet might slow the spread of tumor cells and even suppress their growth altogether.

The reason? Researchers have demonstrated it might have to do with the glucose-dependent metabolism of cancer cells, and depriving cancer cells of glucose could cause oxidative stress in cancer cells but not in healthy cells. This metabolic change caused by the keto diet could even make cancer cells more responsive to radiation and chemotherapy.  

May Reduce Inflammation Caused by High Blood Sugar

The ketogenic diet helps reduce your insulin levels. Irregularly or chronically high insulin levels trigger various health problems like diabetes and cancer.

There is also evidence that the ketogenic diet can reduce your overall insulin sensitivity, which makes it easier for your body to process carbohydrates effectively.

Helps You to Kick the Sugar Habit

The average American consumes about 152 pounds of added sugar in one year. That is three pounds of sugar in one week. That is seven to ten times more than the recommended limit.

But following the ketogenic diet may make it easier to fight off sugar cravings because each meal leaves you satiated. As the diet restricts your carbohydrate intake to 25 grams per day, you’ll cut your sugar intake down to almost nothing, which makes it easier to quit the habit altogether.

May Increase Female Fertility

Over 10% of American women under 44 struggle to conceive or carry a pregnancy to term.

Since the ketogenic diet alters a person’s metabolism, many find that following the ketogenic diet seems to help some of the underlying issues with fertility. The eating strategy positively affects weight and insulin levels, and it can regulate the hormonal effects of polycystic ovarian syndrome (PCOS).


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No diet is perfect, and the ketogenic diet has its share of downsides.

Most Initial Weight Loss Is Water

It’s not uncommon to experience dramatic weight loss when you first go keto, but the initial reason for that loss is temporary.

These initial losses are primarily attributed to water weight from burning your glycogen stores. If you add carbs back to your diet, some of those pounds will return.

Long-term Research Is Limited

Despite the diet’s popularity today, little is known about the effects of the ketogenic diet on your health over time.

This leaves researchers with more questions than answers about its effectiveness after years or decades of commitment. There is a lack of conclusive evidence about whether ketogenic followers will regain the weight or suffer other health consequences, meaning that following the eating method today might potentially put you at risk in the future.

The Diet May Trigger Brain Fog

Your brain is primed to run on glucose, and limiting this supply can affect your mental functioning. This is because your body struggles to transition from using an available energy supply to making its own, which can affect brain functioning in ways that lead to memory loss, headaches, slower cognition, and general “brain fog.”

These effects are usually temporary, and they dissipate once the brain adjusts to burning ketone bodies instead. However, those who are predisposed to mental health issues like anxiety and depression might feel these effects more acutely, meaning that the ketogenic diet might not be the best choice for them.

At Risk of Intake of Some Nutrients

The keto diet limits the consumption of carbohydrates to about 5% of total calorie intake.

While we often think of bread, rice, and pasta when we think of carbs, many fruits and vegetables are also sources of carbohydrates. At the same time, however, fruits and vegetables are very nutrient-rich, and they are important sources of vitamins, minerals, and other phytochemicals.

In people following the keto diet, intakes of vitamin A, C, K, folate, and fiber, among others, are usually low.

Following the keto diet without paying special attention to your intake of micronutrients could lead to long-term health problems.

Easy to Overconsume Saturated and Trans Fats

The ketogenic diet prioritizes fats above all other macronutrients, but it can be hard for beginners to know that not all fats are metabolized in the body in the same way. Eating foods that are sources of saturated fats (especially animal-based saturated fats) may lead to an increased risk of heart disease and cancer.

Many people who try the keto diet may choose conventional animal fats and processed fats over quality fats and oils like those that come from plants and organic or grass-fed animal products.

Potentially Dangerous for Those at Risk of Eating Disorders

The ketogenic diet, as with some other diets, requires careful scrutiny of each meal you eat, which can pose a problem for those with a history of disordered eating.

Some people following this eating plan can lead to compulsive and obsessive behaviors. Categorizing so many foods as “off-limits” can lead to negative associations with food that are physically and mentally damaging. Likewise, failing to follow the diet perfectly might lead to feelings of guilt and inadequacy, all of which should be carefully weighed before beginning.

Might Trigger Kidney Stones

Between 3% and 10% of people who follow the ketogenic diet for months at a time develop kidney stones, partly because of its lack of fiber. You can reduce your risk by ensuring that you stay hydrated and eating those foods that are keto-approved with higher fiber content or taking a fiber supplement.

Might Cause Digestive Distress

When you first transition to keto eating, the high-fat, low-carb diet has the potential to lead to digestive problems like diarrhea or constipation.

The symptoms typically disappear after a few weeks, but they can be alarming at first.

It is important to stay hydrated and to consume fiber and electrolytes when you are on the keto diet.

Bad Breath Is Common

One temporary, yet inconvenient, side effect of entering ketosis is bad breath. This happens because your body is breaking down acetoacetic acid, which many people say produces a similar smell to nail polish and can taste metallic.

Your urine, while you’re in ketosis, often smells the same way.

Ketosis Could Affect Your Athletic Skills

The evidence is mixed about how the ketogenic diet affects athletic performance, and some people find that this eating strategy hurts their results.

Athletes that are looking to maximize their power may struggle to put on weight and improve their strength with a low-carbohydrate diet, but endurance athletes that need to sustain their energy for long periods of time might become more efficient if they fuel themselves on fat stores.

Even so, the diet is more difficult for athletes to follow than less active people because athletes’ bodies demand more energy, and your body might have trouble metabolizing high quantities of fat at first.

You Might Get the “Keto Flu”

As your body acclimates to the ketogenic diet, you might go through a period of transition that leaves you feeling weak and exhausted. Followers of the eating plan call this the keto flu, and it can leave you feeling weak, lightheaded, irritable, mentally slow, constipated, and lethargic. The symptoms usually subside within a few days to a few weeks.

Dos and Don’ts of the Keto Diet

If you’re ready to try the ketogenic diet after reading this overview, then it is important to set yourself up for success from day one. Below are some dos and don’ts to keep in mind as you transition into the keto diet.


  • Stick with healthy fats like eggs, avocado, and extra virgin olive oil.
  • Eat low-carb greens as much as possible to maximize your nutrient intake.
  • Eat berries regularly, one of the few keto-approved fruits that are high in nutrients.
  • Eat real food made from whole ingredients (nothing processed).
  • Source organic, grass-fed animal products as much as possible.
  • Stay hydrated—it helps offset the loss of fiber in your diet.
  • Keep a food journal to track how you feel over time.
  • Consider a modified keto diet if the restrictions are too severe.
  • Consult with your doctor before beginning if you have underlying medical conditions.
  • Always read the nutritional information of foods before you eat them.
  • Consider nutritional or health coaching to ensure you follow the eating plan correctly.
  • Replace your electrolytes by drinking bone broth and eating nuts, seeds and cacao powder


  • Don’t follow the keto diet if you have a history of pancreatic disease, liver conditions, thyroid problems, eating disorders, or gallbladder disease.
  • Avoid eating fast food as much as possible.
  • Avoid trans fats.
  • Avoid any processed food listed as low-fat.
  • Don’t overeat. The high satiety of keto-friendly food might mean that your place looks emptier at mealtimes than it did before.
  • Don’t stress about calories. There’s little reason to monitor your amounts if your macronutrient ratios are where they should be.
  • Don’t follow the keto diet if your doctor has advised you against it.  

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