Keto diet pros and cons

The Keto Diet Pros and Cons

In keto, fat becomes your best friend.

Sounds crazy? It does, but it is true. In the keto diet, you can enjoy eating enjoying bacon, avocado, cheese, and many other high-fat foods while losing weight.

Keto is a delicious and physically satisfying diet. Perhaps this is why keto is one of the trendiest diets.

Some doctors, dietitians, and other health experts recommend the keto diet for many of their patients. However, many other experts and reputable organizations do not recommend this diet.

So, is the keto diet good or bad for you? Unfortunately, the answer is not straightforward. Like in most other diets, there are pros and cons to the keto diet.

On the one hand, this diet is easy to follow as many feel happy with the food selection. Plus, the type of foods in the keto diet creates changes in the body, resulting in decreased hunger and early satiety (feelings of fullness).

Moreover, research suggests that the keto diet results in weight loss, lower blood glucose, and improve brain health, among other health benefits. However, please keep in mind that the amount of research is still limited.

On the other hand, eating so low in carbohydrates (carbs) is very difficult to sustain long term. Plus, there are some significant concerns about how this diet can affect people’s health with certain diseases.

Additionally, nutrition deficiencies related to keto diet restrictions are concerning as many nutrients are primarily found in foods that contain carbohydrates.

It is confusing! Should you follow the keto diet or not?

To help you make an informed decision, let’s explore the keto diet pros and cons in more detail.

What Is the Keto Diet?

The ketogenic diet (or keto) is a high-fat, moderate protein, and low carbohydrate diet. It is different from other forms of low carbohydrate diets because of the very high-fat content.

A typical breakdown of the keto diet is the following: fats (70-80%), proteins (10-20%), and very low carbohydrates (5-10%) of the total calorie intake (1).

What do those percentages mean?

Think about it like this: if you choose to eat only bacon as your form of fat, you could eat 57 thin slices of bacon a day. You could also eat some protein and a tiny amount of carbs (about one fruit and a medium sweet potato).

Compared to a regular diet, the distribution of macronutrients is significantly in favor of fat. In contrast, the number of carbohydrates typically consumed in this diet is very low, normally between 20 to 50 grams.

As a result, the body enters a metabolic state called ketosis, where your body burns fat instead of carbohydrates for energy. This state of ketosis creates ketones, which it can use as the energy source for the body (2).

Symptoms of ketosis include thirst, dry mouth, frequent urination, and decreased hunger and appetite (3).

Read the last part carefully: decreased hunger and appetite. That makes the keto diet easy to follow in the short term.

Curious about the keto diet? Let’s dig further into the keto diet’s pros and cons.

Keto Diets Pros and Cons

Keto diet pros: feeling less hungry

Keto suppresses appetite and enhances satiety

As mentioned before, ketosis is the desired result of the keto diet and results in decreased hunger and enhanced fullness. So naturally, people following the keto diet eat less without any struggle.

In addition, keto dieters feel less hungry because the small number of carbohydrates can potentially decrease the appetite-stimulating hormones insulin and ghrelin (4).

Awesome, right?

Keto weight loss

Keto diet pros and cons

In the short term, studies suggest that the keto diet produces rapid weight loss while preserving muscle mass (5).

Research also suggests that in a period shorter than six months, low calorie, low carbohydrate diets (like keto) result in greater weight loss than low calorie, higher carbohydrate, low-fat diets (6).

At 6, 12, and 24 months, weight loss on a low-carb diet is comparable to other diets (6).

Considering that different diet approaches can work on short and long-term weight loss, the best thing is to think about your personal preferences and health when selecting an eating style.

Keto diet and heart health

A report published in the American College of Cardiology Journal concludes that ketone bodies can help protect the heart in people with cardiovascular disease. (7)

However, a review of 8 large research studies revealed that at 6 to 24 months, people on the keto diet had significantly higher LDL cholesterol than those in higher carbohydrate diets (8).

Contrary to the results mentioned above, other reviews showed no significant difference in total cholesterol and LDL between low carbohydrate diets and other diets.

Furthermore, other studies showed significant improvements in HDL cholesterol and triglycerides with the low carbohydrate diets. However, the difference was not significant at 24 months (9).

The review authors pointed out that while participants followed the keto diet earlier in the studies, adherence to the diet decreased over time. Thus, it is difficult to determine the true impact of a keto diet on lipids, cholesterol, and overall heart health.

Keto diet and blood glucose

The ketogenic diet may be beneficial for type 2 diabetics to help them maintain glucose levels within a normal range because the diet lowers the carbohydrate intake.

Early research has found that ketogenic diets can help control the level of HbA1c – the glucose traveling in the blood during a three months period (10).

However, keep in mind that there are not enough studies to scientifically conclude that the keto diet is beneficial for people with diabetes.


Because of the minimal amount of carbohydrates in the keto diet, people taking blood sugar-lowering medications must consult their health care provider before starting the diet. The role of these medications is to help the body process carbs. Thus, if there is medication in the body but enough carbohydrates, the blood sugar can lower to a dangerous level resulting in a medical emergency with serious health consequences.

Keto diet and brain health

A keto diet may improve neurological conditions like Alzheimer’s disease (11) and Parkinson’s disease (12).

Keto flu

One of the ketogenic diet cons is the keto flu, an unpleasant side effect experienced when initiating the diet due to the low carbohydrate intake. This keto con includes nausea, vomiting, headaches, fatigue, dizziness, insomnia, difficulty in exercise tolerance, and constipation.

Generally speaking, these symptoms resolve in a few days or weeks and can be minimized by drinking enough fluids and consuming enough electrolytes (13).

Keto and the GI system

Some people on the keto experience GI issues, including diarrhea, constipation, vomiting, and abdominal pain.

The keto dieters eat a very high amount of fat, and some people will have issues digesting the fat, especially if the person had a moderate intake of fat before starting the diet. The issue will likely pass, but this diet is not for everybody.

In addition, a 2019 study found that diets high in fat can cause inflammation of the GI tract (your intestines), causing a decrease in your good bacteria, which is important for your overall health (14). Of course, other studies show the opposite that the diet might have good effects on gut bacteria (15).

Another issue found with the keto diet is that many people on this diet consume more artificial sweeteners, resulting in diarrhea (16).

Keto diet and nutrition deficiencies

The keto diet is very restrictive, with a minimal amount of carbohydrates and large amounts of fat. Furthermore, it cuts back on foods high in fiber, vitamins, and minerals.

As a result, keto dieters are at higher risk for nutrition deficiencies. Thus, it is likely that you will need to take fiber supplements to relieve constipation and multivitamins with minerals to prevent deficiencies. Some of the most common nutrient deficiencies include vitamin A, vitamin C, vitamin K, and folate (17).

In the long term, nutritional deficiencies of the keto diet can lead to kidney stones, liver disease, and diseases related to deficiencies of vitamins and minerals.

Keto diet and social life

If you are following a keto diet, social gatherings might be more challenging. However, it might be easier to find keto-friendly foods now that the diet has become so popular.

The bottom line

There is no conclusive evidence that the diet is good or bad. However, further research is needed to understand the keto diet pros and cons of the diet in the short and long term.

However, if you are a healthy individual, most likely you will be fine in the short term.

Keep in mind that you will need to be in ketosis for the diet to work. Thus you will need to follow the diet as is.

Now, if you are taking medications that lower your blood glucose, like insulin, it is best that you follow this diet under the supervision of a registered dietitian and a physician.

If you have liver disease, eating disorders, issues with your pancreas, or eating disorders, then the keto diet is not for you as it can have a severe negative impact on your health.

Last, endurance athletes might also need to consult a health professional well versed on the effects of the keto diet as this diet might decrease their alethic performance. Thus, the keto diet pros and cons must be carefully explored in relationship with athletic performance.

Is the Keto Diet Safe?

In the long term, the keto diet can lead to kidney stones, liver disease, and diseases related to deficiencies of vitamins and minerals. In addition, the risks of consuming such a high-fat diet in heart health are not well studied.

Last, the keto diet is not recommended for those with the following chronic diseases (19):

  • Liver conditions
  • Pancreatic disease
  • Thyroid problems
  • Eating disorders
  • Those without gallbladder

Keto 101

Keto is a high-fat, moderate protein, and low-carb diet. It is different from other forms of low carbohydrate diets because of the very high-fat content.

What Foods Can You Eat in the Keto Diet?

MeatBeef, chicken, turkey, veal, buffalo meat, etc.
Cured meatsBacon, sausage, ham, etc.
Fish and seafoodSalmon, tuna, trout, mackerel, shrimp, scallops, octopus, calamari, etc.
EggsEggs, egg products, and foods made with eggs.
CheeseUnprocessed cheese like cheddar, cream, glue, and mozzarella.
FatButter, cream, ghee.
OilsCoconut oil, olive oil, grape-seed oil, and avocado oil.
AvocadosAll types.
NutsAlmonds, Brazil nuts, walnuts, flaxseeds, pumpkin seeds, and others.
SeedsChia, sesame, and others
VegetablesAll low carb: green leafy vegetables, tomatoes, onions, peppers, etc.
CondimentsSalt, pepper, herbs, and spices.

What Foods Do You Need to Limit in the Ketogenic Diet?

The most important aspect is to meet the macronutrient goals. Remember that to reach ketosis, you will need to limit sugar and carbohydrates.

Sugary FoodsCookies, ice cream, cake, candy, jam, jelly, and other preserves with added sugar, canned fruit packed in sugar, pastries, donuts, milkshakes, and ready-to-eat cereals.
Sugary beveragesSoda, energy drinks, fruit juice, etc.
GrainsBread, rice, pasta, cereal, and all types of grains -including whole grains.
FruitsAll, except small portions of berries.
Beans and LegumesBlack beans, kidney beans, lentils, peas, chickpeas, and all beans and legumes.
Root vegetablesPotatoes, malanga, sweet potatoes, carrots, and others.
Condiments with added sugarBarbecue sauce, ketchup, honey mustard, teriyaki sauce, etc.
AlcoholBeer, wine, mixed drinks

Sample Meal Plan


  • Avocado and eggs
  • Bacon and cheese egg omelet


  • Cobb egg salad
  • Shrimp lettuce wraps


  • Lemon butter fish
  • Keto chicken enchilada

Alcohol and the keto diet

Alcohol Consumption is permitted on the keto diet but in pure forms of alcohol like gin, tequila, rum, whiskey, and vodka. These are low-carb and therefore approved.

These beverages may be consumed alone or with low-carb mixers to enhance the flavor. Keto-approved mixers include seltzer, sugar-free tonic water, diet soda, and crystal light drink mix.

Non-keto-friendly beverages include those made with sugar or other carbs; for example, margarita, bloody mary, sangria, piña colada, vodka with orange juice, rum and coke, Smirnoff Ice, and regular beer.

My personal opinion as a nutrition expert

Overall, as a doctor in clinical nutrition, I believe in achieving a well-balanced and healthy diet in the long term. However, I can see how the keto diet can help many reach their goals.

However, this should be a short-term solution with a plan to achieve a better nutrition balance over time.

If you have more questions about the keto diet pros and cons and whether or not it is a good idea for you, check with your health care professional.

Additionally, a registered dietitian and other nutritionists can create a healthy eating plan that fits you well. Just select a health care professional that aligns with your preferences and goals.

To explore other diet options, check our blog posts: keto vs vegan diet, keto vs Mediterranean diet, intermittent fasting for women over 40, anti-inflammatory diet menu, and find food freedom.

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