By Jeni Tackett, Let’s Move Quad Cities Nutrition Blogger
I was recently at a party with a friend who has lost weight on the ketogenic diet. While I understand the allure of losing weight, this diet makes me cringe. There are better, more nutritious and healthier sustainable ways to lose weight. Read on.
I learned about the ketogenic diet 20 years ago when I was in college studying nutrition. Physicians sometimes prescribe ketogenic diets for children with epilepsy to control seizures. The ketogenic diet is now a popular fad for weight loss.
The goal of the ketogenic diet is to put you into ketosis where your body is not receiving energy from glucose (carbohydrates). It forces your body to use fat as fuel, which results in your liver turning fat into ketones.
What is the ketogenic diet?

The ketogenic diet is a high-fat diet with 70-80% of calories from fat. The diet is very low in carbohydrate, with less than 5% of calories coming from carbohydrate. Protein intake is moderate, with 15-20% of calories from protein.
In comparison, the diet recommended by the United States Department of Agriculture and American Heart Association is 45-65% carbohydrate, 20-35% protein, and 10-35% fat.
What do you eat on the ketogenic diet?
You eat many high-fat foods: oils, nuts, avocados, seeds, meat, fish, butter, eggs, heavy cream, and cheese.
What do you avoid on the ketogenic diet?
You avoid grains, beans, potatoes, milk, yogurt, and fruit.
Here are the pros and cons of the ketogenic diet:
Pros:
- You lose weight because you cut calories.
- When you reduce carbohydrate significantly, you end up consuming more protein, which may make you feel more satisfied.
- The state of ketosis can suppress your appetite.
Cons:
- Your initial weight loss is mainly water loss. Any low-carbohydrate diet results in depleting glycogen stores (how the body stores carbohydrate for fuel) in your muscles and liver. When you lose glycogen stores, you lose water as well.
- Not sustainable: This diet is too strict.
- Loss of muscle mass: Carbohydrate intake causes the pancreas to produce insulin. Insulin is required for muscle growth.
- Elevated cholesterol: A 10-year study showed that the ketogenic diet might elevate cholesterol levels. If you have a history of high cholesterol, you may want to reconsider following such a high fat diet.
- Nutrient deficiency: The ketogenic diet is low in fiber and important minerals such as potassium, calcium, and magnesium. These minerals are important for blood pressure control and heart health.
The Worst Cons:
- Bad breath: Being in a state of ketosis results in bad breath.
- Constipation: The ketogenic diet is very low in fiber, which can cause constipation. Constipation is both uncomfortable and can result in health problems such as diverticulosis (pouches in the intestine).
I do not appreciate or support weight loss with no thought to nutrition. The list of allowed foods lacks many nutrients and fiber. Any diet that outlaws healthy foods like fruit, whole grains, and beans does not make sense and is difficult to sustain.
I want people to succeed in losing weight and being healthy, but the disadvantages of the ketogenic diet far outweigh any weight loss.
By choosing high fiber, whole foods and making changes in your habits over time will result in sustainable weight loss that is good for your body.
January 17, 2018 at 4:50 pm
Such uninformed nonsense from someone professing to be a professional. What you were taught 20 years ago was wrong. Have you read “The Art & Science of Low Carbohydrate Living” or it’s follow up for athletes “The Art & Science of Low Carbohydrate Performcance”? Are you aware of the many studies refuting almost all of your “cons” above? You might want to pick up and read “The Ketogenic Bible:The Authoritative Guide to Ketosis” published last year and comprehensively annotated with supporting science.
January 26, 2018 at 10:35 am
Sean-
Nutrition can be confusing. There are books supporting many different fad diets but not supported by long term studies. I am too concerned with the lack of fiber and micronutrients in the ketogenic diet to support long term use. Studies have shown that following this diet for any length of time is difficult. Nutrition does not need to be difficult…it needs to be nourishing and sustainable.
Thank you,
Jeni Tackett
January 26, 2018 at 12:34 pm
Thanks for providing the pro’s and con’s of the ketogenic diet. For me, the loss of fiber and minerals is enough to keep me away from this diet. It sounds like it *might* be a good way for a person to lose weight at first, but not to sustain a long-term healthy diet .
January 26, 2018 at 2:58 pm
Thanks for sharing a professional opinion on this diet! With all the fad diets out there it can be tough to know the pros and cons to each of the options.
January 26, 2018 at 4:39 pm
Thank you again for a well written and informative blog post, Jeni. It seems like there is a new fad diet popping up every other day- I can’t keep up! I’m with Jean, and in my opinion any diet telling you to stay away from healthy things like complex carbs, beans, and fruit and eat things with butter and heavy cream should be enough to give anyone pause. Fad diets may come and go, but a healthy diet is sustainable and lifelong, and I wish more people could see that.
Keep up the wonderful work that you do!
Ali
January 26, 2018 at 7:01 pm
Full disclosure: I am not a licensed RD and I don’t think the one class I took from Mary Ella Higgins at Marycrest in pre-nursing counts. I have spent years reading about nutrition, trying a variety of diets for wellness and sensitivity issues and watching fads come and go over decades of my life. It does not make me an expert but here’s my take: My husband who is an intelligent well read person who I love dearly is on Keto. I tried it and while I did lose weight, I know that for me, the lack of vitamins and minerals found in fruits and vegetables was not working. I believe that any regimen which severely restricts food groups which deliver the nutrients needed for cellular growth and repair is likely not compatible with life on a long term basis. I have read a great deal about this and the longitudinal studies are statistically insignificant in large part due to the non-compliance percentages over decades. The recidivism rates are staggering and the impact to metabolic processing is akin to the well known adversity of severe calorie restriction, In the end, the damage is far worse than carrying a few pounds. I am sticking with the Mediterranean approach which is based on a variety of nutrient dense foods and restriction of processed items posing as food.
Julie
August 3, 2018 at 12:34 pm
Just to let you know, that a Keto way of eating does not include cutting calories. I am eating more calories than I was before starting this way of eating. It is recommended that women eat no less than 1800 calories. You don’t increase in protein consumption because in Keto way of eating you eat a moderate amount of protein. You don’t cut vegetables and fruits. You count how many carbs you eat and try to keep it under 20 but I can eat over 3 cups of salad, broccoli, asparagus, the list is long so I won’t list it all. Im not naturally a vegetable eater so on this diet I’m actually eating more than before. Berries are acceptable fruit and if you watch your carbs you can eat other fruit but don’t want to include those that are high in sugar. My labs for the past two years were better than they’ve been in 10 years or more. I have not had issue with an elevated cholesterol any more than it was before but my good cholesterol is higher and my doctor is quite pleased with my blood work. You didn’t site your source on any of the studies that you talked about so I don’t know about the accuracy. My blood pressure was borderline high but now is consistently 106 to 117 over 65 to 72. Any diet that Ive been on says that the initial weight loss is water weight. Ive tried a lot of diets and I lost and gained the same 20 pounds over and over. I am very active and exercise several times a week including at least 30 miles of bike riding each week. I have a lot more energy but this doesn’t happen if you cheat on Keto and maybe that’s what has happened with the study that you read.When I started the Keto way of eating, I lost 40 pounds in 6 months. That’s not fast and it’s not a fad. I have kept this weight off for 2 years. This diet isn’t for everyone because you can’t eat a bag of cookies or a tub of ice cream then cut calories to make up for it. You goal is to keep yourself into ketosis and it doesn’t happen over night. So just because it isn’t everyone’s cup of tea, you should learn more about it before writing about it. This diet doesn’t cut vegetables and fruit out. It does have vegetables and fruits that are more packed with nutrition. Oh and not everyone gets constipated or has bad breath.. Ive had worse on other diets that I was starving the whole time and couldn’t sustain.
March 3, 2019 at 3:05 pm
Does anyone in the right mind think the USDA is a credible source for healthy diet information? Let’s go spray millions of gallons of roundup on the ground.