Recently, many of my patients have been asking about a ketogenic diet. Is a ketogenic diet safe? Would you recommend it? Despite the recent hype, a ketogenic diet is not something new. In medicine, we have been using it for almost 100 years to treat drug-resistant epilepsy, especially in children. In the 1970s, Dr. Atkins popularized his very-low-carbohydrate diet for weight loss that began with a very strict two-week ketogenic phase. Over the years, other fad diets incorporated a similar approach for weight loss.
What is a ketogenic (keto) diet?
In essence, it is a diet that causes the body to release ketones into the bloodstream. Most cells prefer to use blood sugar, which comes from carbohydrates, as the body's main source of energy. In the absence of circulating blood sugar from food, we start breaking down stored fat into molecules called ketone bodies (the process is called ketosis). Once you reach ketosis, most cells will use ketone bodies to generate energy until we start eating carbohydrates again. The shift, from using circulating glucose to breaking down stored fat as a source of energy, usually happens over two to four days of eating fewer than 20 to 50 grams of carbohydrates per day. Keep in mind that this is a highly individualized process, and some people need a more restricted diet to start producing enough ketones.
Because it lacks carbohydrates, a ketogenic diet is rich in proteins and fats. It typically includes plenty of meats, eggs, processed meats, sausages, cheeses, fish, nuts, butter, oils, seeds, and fibrous vegetables. Because it is so restrictive, it is really hard to follow over the long run. Carbohydrates normally account for at least 50% of the typical American diet. One of the main criticisms of this diet is that many people tend to eat too much protein and poor-quality fats from processed foods, with very few fruits and vegetables. Patients with kidney disease need to be cautious because this diet could worsen their condition. Additionally, some patients may feel a little tired in the beginning, while some may have bad breath, nausea, vomiting, constipation, and sleep problems.
Is a ketogenic diet healthy?
We have solid evidence showing that a ketogenic diet reduces seizures in children, sometimes as effectively as medication. Because of these neuroprotective effects, questions have been raised about the possible benefits for other brain disorders such as Parkinson's, Alzheimer's, multiple sclerosis, sleep disorders, autism, and even brain cancer. However, there are no human studies to support recommending ketosis to treat these conditions.
Weight loss is the primary reason my patients use the ketogenic diet. Previous research shows good evidence of a faster weight loss when patients go on a ketogenic or very low carbohydrate diet compared to participants on a more traditional low-fat diet, or even a Mediterranean diet. However, that difference in weight loss seems to disappear over time.
A ketogenic diet also has been shown to improve blood sugar control for patients with type 2 diabetes, at least in the short term. There is even more controversy when we consider the effect on cholesterol levels. A few studies show some patients have increase in cholesterol levels in the beginning, only to see cholesterol fall a few months later. However, there is no long-term research analyzing its effects over time on diabetes and high cholesterol.
Key takeaways from a ketogenic diet review?
A ketogenic diet could be an interesting alternative to treat certain conditions and may accelerate weight loss. But it is hard to follow, and it can be heavy on red meat and other fatty, processed, and salty foods that are notoriously unhealthy. We also do not know much about its long-term effects, probably because it's so hard to stick with that people can't eat this way for a long time. It is also important to remember that 'yo-yo diets' that lead to rapid weight loss fluctuation are associated with increased mortality. Instead of engaging in the next popular diet that would last only a few weeks to months (for most people that includes a ketogenic diet), try to embrace change that is sustainable over the long term. A balanced, unprocessed diet, rich in very colorful fruits and vegetables, lean meats, fish, whole grains, nuts, seeds, olive oil, and lots of water seems to have the best evidence for a long, healthier, vibrant life.
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shanderM
September 11, 2017
I'm not buying this 'hard to stick with' forgone conclusion. Living off of romaine lettuce and eggs, steak and broccoli, being able to eat buffalo chicken wings or cheeses make for all sorts of alternatives, and really most food does fit.. just bread, rice or root stuff doesn't work.
It's a habit to enjoy a brie cheese for desert instead of a piece of chocolate cake but each are favored deserts in France. I'm personally more satisfied after a 350 calorie sized wedge of brie than the same number of calories of cake.. which will give me sugar crash and .. really I'd like two slices of cake(I've got a sweet tooth that once I get going it wants to keep being fed)
It's no hardship to eat buffalo chicken wings instead of pizza.. they're both indulgences of the same sort and .. just choose the first if you want to remain Keto.
The real key though is the satiety. I find it harder to over-eat the chicken wings that I can with pizza .
Tuna fish with mayo and lettuce or a bowl of pasta with tomato sauce and chicken? Purely preference…. both are rich … it's only a matter of setting a new cuisine preference.
The only issue with keto, is really that I'm afraid that it might be hard to up my calories to a maintenance weight now that I've gotten a taste preference for the rich assortment of foods with no carbs in them. I'm satisfied with less calories than I will need after my excess fat is burned off… but , maybe I bet my body will send more hunger signs once there isn't anymore body fat in the cupboard to use instead of what goes down my throat.
I'm discouraged to see that nowhere in the article nor in the comments is there a mention of a diet's best fit to genetics. Consider if someone is an APOE E2 carrier and/or has certain polymorphisms of the APO5 gene. These are quite rare in Okinawa but much more prevalent in the USA (12% of the population). According to a number of well-designed studies, these genetic characteristics point to a higher fat, lower carbohydrate diet as beneficial and even a 'moderate' carb diet as problematic.
So rather than giving one-size-fits-all dietary advice or weaponizing the word 'balanced' it might be better if the medical community suggested that there are Individual differences that need to be considered. This might also help those lay folk who have had success with one dietary lifestyle or another also realize that what's valid for them may not be good advice for others.
Jack Daniels
September 6, 2017
just to be fair a keto diet has its short term benefits but what the doc is trying to say is that it hasn't been studied long term. I think most studies cover until two years so what happens after that?? in 5 years 10 years???
and for f..sakes nothing beats a balanced diet and exercise. Period.
Mike Harris
September 6, 2017
I've been on the keto diet for 15 months. My triglycerides went from 293 to 71 after four months. I'm 45 years old. I no longer need statins. I haven't felt this good in 20 years. I think I eat less meat then the average American. There's my scientific proof.
Yvette Schlussel
September 5, 2017
Dr. Campos, it is unfortunate that you retain the medical community's negative stance on the ketogenic diet, probably picked up in medical school when you studied ketoacidosis, in the midst of an obesity and type II diabetes epidemic that is growing every year, especially among populations who will never see the Harvard Health Letter. The medical community has failed in reversing this trend, especially among children, and the public is picking up the tab, in the form of higher health insurance premiums to treat chronic metabolic diseases which doctors cannot cure. The ketogenic diet does not bid its adherents to eat unhealthy processed meats, and the green leafy vegetables that it emphasizes are important in a number of nutritional deficiencies. People lose weight on the ketogenic diet, they lose their craving for sugar, they feel more satiety, they may become less depressed, their insulin receptors sensitivity is improved, and these are all the good outcomes you fail to mention. There is a growing body of research which demonstrates the neuroprotective effects of the ketogenic diet to slow cancer progression, as well as diseases like Parkinson's and Alzheimer's, for which there are no effective medical treatments. Please respect your patients by providing them with evidence-based medical outcomes, not opinions.
Yvette Schlussel
September 5, 2017
Here is some of the evidence, by the way:
Ann Intern Med. 2014 Sep 2;161(5):309-18. doi: 10.7326/M14-0180.
Effects of low-carbohydrate and low-fat diets: a randomized trial.
Bazzano LA, Hu T, Reynolds K, Yao L, Bunol C, Liu Y, Chen CS, Klag MJ, Whelton PK, He J.
The low-carbohydrate diet was more effective for weight loss and cardiovascular risk factor reduction than the low-fat diet. Restricting carbohydrate may be an option for persons seeking to lose weight and reduce cardiovascular risk factors.
2)Ann Intern Med. 2004 May 18;140(10):769-77.
A low-carbohydrate, ketogenic diet versus a low-fat diet to treat obesity and hyperlipidemia: a randomized, controlled trial.
Yancy WS Jr1, Olsen MK, Guyton JR, Bakst RP, Westman EC.
Compared with a low-fat diet, a low-carbohydrate diet program had better participant retention and greater weight loss. During active weight loss, serum triglyceride levels decreased more and high-density lipoprotein cholesterol level increased more with the low-carbohydrate diet than with the low-fat diet.
Lucas Medeiros
August 8, 2017
Dr. Campos,
Your article is very good: best evidence-based medicine, avoided 'religious' myths about nutrition, was careful and insightful.
Hope to read more posts of your thoughtful expertise.
Congratulations,
Dr. Lucas Medeiros (from Rio de Janeiro – Brazil)
Robert L. Weiss, L.I.C.S.W., C.A.S.
August 18, 2017
Hi Dr Mederios,
My point here is that the warnings about the ketogenic principles are well taken and well documented. My concern is implications that this is a fad. I don't use the word diet with my patients and I'm concerned that the principles behind the label and the real results that these readers have commented on might get minimized. I have found it best to encourage patients to read authors like: Stephen Phinney, Jeff Volek, Patricia Daly, and Charles Gant and the be partners with their doctors and check blood work as they move along. I am not for or against the article. If ketogenic principles offer people enduring, satisfying, and cohesive change then why not read about its potential and flexilbity?
Robert L. Weiss, L.I.C.S.W., C.A.S.
August 7, 2017
I have great respect for Harvard Medical School. I notice that they support their readers posting comments and I am most appreciative of the article and all the many thoughtful comments by the readers. The readers seem to have the most expertise here and I hope that the doctor who wrote the article will think long and hard about the comments by readers. After 35 years of clinical practice in mental health, I notice that all issues of emotion involve medical issues, nutrition, and the gut bacteria. I would say that these issues and all of the executive brain functions seem to improve with ketogenic principles. For those that apply it in a flexible and smart manner, it appears to improve every area of their lives. I strongly encourage the author of the article to take one class via The Institute for Functional Medicine. If he is open to more learning he can take more classes and get certified. I'm sure a fine doctor, he will be an even better doctor and personally healthier, if he gets more training. Are we all open to new learning(especially us healthcare providers)?
Oscar Bressane
August 3, 2017
Dear Dr. Marcelo Campos.
We are brazilian, living in Brazil. My daughter, Isabel, 21y. o., born in 1996, has syndrome of deficiency of Glut1. She was diagnosed around her first year of life. At that time her baby bottle, her begining diet meal, was 50ml water plus 50ml oil plus vitamin. Since then, which means, for 20 years, she is under this diet. For almost 18 years under 4:1 proportion. At this right moment 3:1. The only problem she had since started the diet were kidney stones in 2002. Nothing else. Grateful to the diet she doesn't take any kind of medicine to avoid seizures. Her health is perfect, no colesterol at all. We are at your will for any issues related to her health.
Dr. Campos is objective in his presentation, but some of the comments in favor of ketogenic diets are rather exalted in tone. Perhaps a good diet would simply be one where you eat moderate quantities of the basic food groups and exercise a couple of hours a week.
It is a diet that tells you to cut out sugar and starch. So no more doughnuts. Nothing wrong with that!
Nobody is obliged to consume huge quantities of meat, and meat products. You seem to have a knee jerk bias against this diet because it works, and the usual waffle about 'moderation' does not.
Keto is not hard to follow at all. See, this is why I took my diet and nutrition into my own hands. I have PCOS and the ketogenic diet has worked wonders for me. I'm finally pregnant at the age of 32 and after 11 years of marriage because the ketogenic diet made me lose over 100 lbs and brought my insulin resistance under control. I feel better than I've ever felt. Sometimes doctors don't seem to know as much as they should, or as much as they assume they do, and that's pretty disturbing. Just like they're still using the old school and very inaccurate BMI charts that are just pure bs. I'll just take care of myself outside of certain situations involving illness or injury. I'm doing great on my own.
Bernard Berger
August 1, 2017
Isn't the Atkins diet the traditional Eskimo diet which Eskimos have eaten for countless generations? Almost nothing grows in Northern Alaska, so the Eskimo diet is almost entirely from meat & fish. Shouldn't be too hard to study.
there is adaptation,see darwins finches
Yes you can lose fat on a low carb because it's just another low calorie diet. How do I know this? I've done low carb, (Atkins, etc) high carb, (Slimming Word) moderate carb etc and log my food and was shocked each time to see they were all low calorie. After the initial week or so the rate of fat loss is same as any other diet. It's calories in calories out. Simple. It's what some call indirect deficit diet placing silly restriction, rules can eat must eat etc. and of course you lose weight but nothing to do with low carb. It works because it's a low calorie diet.
Claudia Groposo
August 1, 2017
I'm following the ketogenic diet and I find it very easy, pleasant and varied. I can even say that my diet today is more varied than the previous one. I do not intend to leave this diet and I cannot really see why. My initial focus was not to lose weight, I've always been lean, but to feel better, well disposed. And I got it! I am very pleased, I have read a lot about it (including scientific literature) and I have influenced other people who need to lose weight or improve some aspects of their health. But from the beginning I went on my own way, without the help of a nutritionist because I did not want to suffer the influence of others' ideas.
Miriam Kalamian
August 1, 2017
Dr. Campos, it is so discouraging to see that you disparage the ketogenic diet based on your assumption that it is very heavy in poor quality processed meats. No diet that relies on processed foods can be viewed as 'healthy'. Become better informed by getting up to speed with what Jeff Volek, RD, PhD, calls a 'well-formulated ketogenic diet.' Also, learn more about the potential of the diet to slow cancer progression (my specialty). You owe it to your patients who are depending on you for advice. Present them with facts, not opinions.
Thank you.
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