While the ketogenic (or keto) diet is being considered one of the most popular diets today, the truth is that it has been used originally as a form of epilepsy therapy back in the 1920s and 1930s (*).
Like any health-promoting diet out there, the keto diet has advantages and disadvantages depending on the person using it. This includes their current health status and whether they follow it properly and rely on the best practices.
This article explores a list of ketogenic diet pros and cons to help you decide if this way of eating is right for you.
The keto diet requires cutting carbs to 50 grams per day to reach ketosis, which is characterized by increased ketones in your blood, breath, and urine. When you’re in this metabolic state, it means that your body is burning fat for fuel instead of glycogen — the storage form of carbs.
Since carbs are limited on keto, most of your calorie needs for the day will come from fat while protein is consumed in moderate amounts to maintain function and preserve muscle (*).
Therefore, your food will include a variety of meats, seafood, fish, poultry, eggs, leafy greens, nuts, seeds, and non-starchy fruits. When it comes to fat, it’s crucial to avoid bad fats like vegetable oils — soybean oil, corn oil, canola oil, and sunflower oil — since these fats cause inflammation and increase your risk of disease (* , *, *).
Aside from bad fats, high-carb foods aren’t allowed, such as grains, sweet fruits (like apples, mangoes, bananas), juices, traditional baked goods and desserts, and starchy veggies (like corn and potatoes).
Research indicates that the keto diet leads to weight loss, helps with controlling blood sugar, reduces inflammation, manages seizures, and eliminates digestive issues related to FODMAPs. Here’s more about each benefit:
1. Short-Term and Long-Term Weight Loss
Weight loss is one of the most popular keto diet benefits that people seek.
Many people experience rapid weight loss — up to 10 pounds within 2 weeks or less — due to the diet’s diuretic effect. Meaning, that you initially lose water weight as a result of glycogen depletion (*). (Note: glycogen is stored with 3-4 grams of water inside your liver and muscles.)
This initial weight loss is then followed by a slower weight loss, although this time you’re now losing body fat and not water weight.
When it comes to sustaining weight loss, one randomized controlled trial found that obese patients lost more weight doing low-carb for 6 months than those on a conventional diet. Furthermore, the subjects on low-carb had higher HDL “good cholesterol” levels and better blood pressure throughout the study (*).
2. Reduced Blood Sugar Levels
Glucose is essential to the body, but too much glucose in the blood (caused by a high-sugar diet) leads to problems in your energy levels and mood. Not to mention, it’s associated with inflammation, obesity, and insulin resistance (*).
Eating fewer carbohydrates can be especially beneficial for avoiding these health issues. It becomes even more important if you’re trying to avoid diabetes or manage it effectively — or reverse it, for type 2 diabetes patients.
A 10-week study was done on adults with type 2 diabetes who consistently restricted carbohydrates. After 10 weeks, results showed reduced HbA1c levels (a reflection of your average blood sugar over the past 2-3 months). In addition, participants were able to reduce or eliminate their diabetes medications (*).
3. Lowered Inflammation
Chronic inflammation drives diseases, such as cardiovascular disease, cancer, non-alcoholic fatty liver disease (NAFLD), Alzheimer’s disease, and autoimmune disorders.
Study shows what you eat can cause inflammation in your body. For example, refined grains, and high-glycemic load foods (like white rice, breakfast cereals, and sugars in highly processed foods) activate inflammatory genes (*).
Reducing your carb intake, especially sugars and carb-rich processed foods, can be an important factor in preventing disease and maintaining optimal health.
4. Effective for Managing Seizures
As mentioned earlier in this article, keto has been used in the 1920s to treat intractable epilepsy (or epilepsy that can’t be controlled by medications) (*).
This is because the diet changes the way the brain uses energy. It shifts energy metabolism away from glucose and towards dietary fat (*). Furthermore, the “low sugar” component of the keto diet reduces neuronal excitability, which leads to fewer seizures (*).
5. Naturally Low in FODMAPs
The term “FODMAP” stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. In essence, FODMAPs are poorly absorbed carbohydrates.
Eating them may cause digestive problems in people who cannot tolerate them, such as bloating, flatulence, diarrhea, constipation, and cramping. Since the keto diet involves cutting carbs, it naturally eliminates most high-FODMAP foods like apples, oats, grains, and pineapples (*).
Therefore, if you’re suffering from irritable bowel syndrome (IBS) or gastroesophageal reflux disease (GERD), following a keto diet — and making more modifications for optimal relief — may help (* , *).
Some people who try the keto diet may decide to quit or claim that it has caused them problems. Disadvantages usually result from not following the diet properly.
For example, they focus on low-carb but highly processed foods or do not pay attention to their micronutrient needs, which is important in any diet. Another common concern is the keto flu, which consists of temporary headaches, weakness, and other symptoms.
We’ll discuss each concern below and address them accordingly.
1. The Keto Flu
The keto flu is a group of side effects that include headaches, fatigue, dizziness, irritability, and digestive discomfort (*). These symptoms are temporary and are your body’s reaction to its new fuel source (fat).
However, they can make new dieters give up, especially if the symptoms are severe.
Fortunately, you can combat the keto flu by getting lots of rest, staying hydrated, taking electrolytes, and increasing your fat intake for extra energy.
Also, you might want to consider reducing carbs gradually for a slower transition — this may also lead to fewer or less severe keto flu symptoms.
Note: Dehydration caused by the keto flu can cause you to develop kidney stones. Check the color of your urine to know your hydration status. Ideally, it should be pale yellow and not dark yellow.
2. Health Risks Linked to Processed Foods
There are two ways to approach keto. You can do it the “clean” way (a.k.a clean keto), where you eat mostly unprocessed whole foods, or the “dirty” way, where you eat processed foods (a.k.a. the dirty keto diet).
While the dirty keto approach offers convenience, it’s no secret that relying on processed foods has health risks. Processed foods have been stripped of their vitamins and minerals, which could lead to nutrient deficiencies. Moreover, they contain preservatives and artificial colors (*).
If you want to boost your health on the keto diet, avoid processed foods or consume them only occasionally (during emergencies or when you really can’t do meal prep).
3. An Obsession with Food
Food is meant to be enjoyed. But, unfortunately, some people find the keto diet too restrictive, and feelings of deprivation may lead to an eating disorder.
Personality traits such as negative emotionality (moodiness, anxiety, worry, and envy) and perfectionism can put a person at risk of disordered eating (*).
If you have a history of an eating disorder, the keto diet may not be the best option for you.
4. Possible Nutrient Deficiencies If Done Incorrectly
A well-formulated keto diet emphasizes meeting not just your macronutrients, but also your micronutrients (vitamins and minerals). This will support your health and physical performance, and it makes the keto diet sustainable long-term.
Nutrient deficiencies may result from calorie depletion, especially if you cut calories often. Restricting calories isn’t required to achieve weight loss and better metabolic health on keto. However, you should be mindful not to eat beyond satiety (*).
Important: Weigh up these keto pros and cons before deciding if it’s the best fit for you. Unless you have (or are at risk for) a health condition that will benefit from cutting carbs, removing a food group from your diet may not be necessary.
Here are answers to common questions on the keto diet pros and cons:
Do doctors recommend keto?
Some doctors recommend the keto diet while others don’t. It depends on your doctor’s personal experience with the diet, their current knowledge, or all of the above. Those who do, usually recommend it as a dietary strategy to control blood sugar levels and reduce body weight in obese individuals.
How long should you be on the keto diet?
You can follow the keto diet for as long as you find it to be helpful for staying healthy and meeting your personal goals. Some individuals do keto for years while incorporating carb-up days (days when they eat more carbs, specifically healthy carbs) to get a temporary break from the diet while also boosting their performance at the gym.
What are the long-term effects of keto?
In a one-year study, patients with type 2 diabetes who restricted carbs were able to normalize their hemoglobin A1c level (below 6.5%), lose weight, and stop taking most of their blood sugar control medications. What’s also surprising is that the majority of participants stuck to the diet for the full year despite the requirements (*).
When it comes to choosing a diet that’s right for you, take time to consider your current health condition, food preferences, studies available on the diet, and diets you’ve probably tried in the past — among other factors.
If you think that the ketogenic diet can help, go and give it a try. You may also want to discuss it with your healthcare provider if you’re currently taking medications.