Insulin allows sugar in our blood to enter our cells. When insulin attaches to the insulin receptor, it activates a series of enzymatic reactions, which ends with active glucose transport (a gateway for glucose to enter the cell). If our insulin receptors are covered in fat, we end up with high blood sugar, because insulin can’t enter our cells. This is called insulin resistance. This fat is called intramyocellular lipid, or fat inside our muscle cells (10).

I can tell how passionate you are about this subject. As you can see on one of my reply’s above, CDE’s do not recommend the same number of carbs for every person we see; we use an individualized approach. It varies depending on the person’s height, bone structure/muscle mass, amount of weight they may need to lose (or gain) and the amount of exercise they may or may not do per day/week.
"That being said, using this diet as a kick start for two weeks and then following it with a healthier way of eating is not a bad thing," Amselem says. "For example, one can start on the ketogenic diet for a two-week period and then follow a plan that is healthy and sustainable for life by limiting the high-fat red meat and dairy and adding fish, olive oil, fruit, and healthy carbohydrates such as whole grains, sweet potato, brown rice and quinoa."
The keto diet dates back to the 1920s, explains Michelle Hyman, MS, RD, CDN a registered dietitian at Simple Solutions Weight Loss. "The original keto diet was designed for patients with forms of epilepsy that were resistant to standard treatments. The macronutrient breakdown was designed to mimic the fasting state — which seemed to help with relieving seizures — yet provide energy and nutritions to function," Hyman says.
One of the keto researches commented, (I think it was Steve Phinney) that change will come about only because enough of the the public will be become educated about this and will demand that the ADA change their recommendations because those recommendations are just wrong. What is the proof they are wrong? If you eat 45-60 g of carb daily, you will continue to have diabetes, and the epidemic will continue as it has for the last 25 years.
Answer: No—unless you do it for more than a few months. After a few months, the upfront metabolic and weight benefits will begin to reverse and new health problems arise. We know this with confidence. I raise this question once again because more and more people are coming to me reporting problems. It may take months, even years, but the long-term consequences can be quite serious.
I suffered through a year on 20 grams of carbs per day and it was the worst year of my life. Yep, I lost weight, but at my current weight of 130 lbs and eating 30 carbs per meal and remaining in a prediabetes state for 15 years, I am healthy AND happy now. None of us know the long term effects of most of what is offered to us…medications, diet drinks, processed foods, restrictive diets. The point I was trying to make was eating healthier, more natural foods will be better in the long run, I believe we all have the common sense to agree on that, even if we can’t agree on how many carbs we will eat!
The keto diet works by eliminating carbohydrates from the your daily intake and keeping the body’s carbohydrate stores almost empty, therefore preventing too much insulin from being released following food consumption and creating normal blood sugar levels. This can help reverse “insulin resistance,” which is the underlying problem contributing to diabetes symptoms. In studies, low-carb diets have shown benefits for improving blood pressure, postprandial glycemia and insulin secretion. (7)
ME: It is not essential. You can be fully ketogenic without any intermittent fasting. However, most people find it natural to do intermittent fasting as their hunger is reduced to where they don’t need a third meal. Keeping feeding time reduced to a smaller window during the day enables the body to use stored body fat for fuel longer, which benefits weight loss. My husband Craig and I still do intermittent fasting every day as maintenance. It just makes life easier only having to make two meals a day instead of three.

You might be surprised to learn that many non-keto friendly foods are associated with a whole lot of health benefits – so by cutting them out, you forgo many of their perks. Fruit, for example, is brimming with a range of antioxidants that help to fight damage to your body’s cells. Another example is grain foods, which are associated with reduced risk of heart disease, diabetes and some cancers. Same goes for legumes, too.
That makes a lot of sense. Keeping up insulin pathways when you aren’t eating carbs would be like keeping the lights on when it’s daytime outside — it’s a waste of energy. You aren’t using insulin on keto, so your body probably downregulates your insulin pathways. As a refresher, insulin is a hormone produced by your pancreas that tells your cells to absorb glucose to use as fuel. When you eat carbs, insulin production begins. In the absence of carbs, there’s less need for insulin.
You lose weight temporarily because “if you’re not hungry every five minutes and can work on your willpower,” you won’t eat as much, Nisevich Bede says. But while some research is promising — one study published in October 2013 in the British Journal of Nutrition found that the keto diet led to greater weight loss than a low-fat diet, for example (4) — there is a lack of long-term research (greater than two years) that suggests a highly restrictive diet like keto is superior for weight loss than others, and it’s certainly not right for everyone.
“The major benefit of the keto diet is that it does work so you lose weight,” says Ms. Zarabi. “But then again, it is a diet and like all diets, it is a short term solution, something you do, then you stop. It is not really a sustainable diet in real life situations. More importantly, your goal is not just to lose weight—anyone can lose weight. The more necessary goal is to keep the lost weight off.”  
Researchers who set out to review the current state of research as it relates to the ketogenic diet published their results in the highly respected European Journal of Clinical Nutrition. Their comprehensive evaluation showed that the ketogenic diet held promise in a vast array of medical conditions and is promising results in other conditions, such as:
Purnell JQ, Hokanson JE, Marcovina SM, Steffes MW, Cleary PA, Brunzell JD. Effect of excessive weight gain with intensive therapy of type 1 diabetes on lipid levels and blood pressure: results from the DCCT. Diabetes Control and Complications Trial. JAMA. 1998;280:140–146. doi: 10.1001/jama.280.2.140. [PMC free article] [PubMed] [CrossRef] [Google Scholar]
In a survey of both children and adults, researchers found that a very low carbohydrate diet promotes “exceptional glycemic control” in those with type 1 diabetes mellitus. When it comes to type 2 diabetes, the Journal of American Medical Association recently published a review examining the effective use of the ketogenic diet in those with type 2 diabetes.
Sustainable is Key. Thank you for the article, it explained so much! I have been inclined to follow this diet but what has worked for me before is a diet that’s called “The AntiDiet” and is simply starting your day with fruits, while strictly separating complex carbs and proteins during lunch and dinner, and still being opened to consume all kinds of food. I had been trying the Whole30 for so long and so many times and I simply can’t, does not make sense for me and so does Keto in the sense of overloading on fats and meat. Thank you!

The most obvious sign that your electrolyte/mineral balance is being affected is an increase in urination. On a low-carb diet, insulin levels drop which promotes the secretion of sodium in the urine. Sodium pulls more water into the urinary system which then is excreted as well.  This is a very normal one of the keto side effects and a positive sign you are moving towards keto adaptation.
Can’t you take ketone supplements? No. While it is possible to elevate ketones by taking them, “without the low-carb stimulus, there is no net increase in ketone production, no decrease in insulin, and no net increase in fat oxidation,” says Volek. Don’t trust trainers or “body hackers” who say you can induce ketosis quickly without changing your diet.
Missing Nutrients. One of the biggest concerns for dietitians is the keto diet’s lack of key foods. Many question the eating plan’s impact on the development of certain chronic diseases. Without milk, for example, getting enough calcium and vitamin D for sturdy bones becomes a challenge. Take away whole grains, fruit, beans, and potatoes, and it’s nearly impossible to consume enough potassium for healthy blood pressure or enough fiber to stay regular. And unless you’re eating lots of low-carb, leafy green vegetables, you miss out on vitamins A, C, K, and folate, too. 
The keto diet is an ultra-low-carb and high-fat diet that restricts total carbohydrate numbers to just 20 or 30 net grams of carbohydrate per day. That’s the equivalent of a single piece of fruit or half a bagel. When you cut carbs, your body’s preferred source of energy, you require your body to suddenly shift to fat for fuel. This raises blood levels of ketones and puts you in a state of ketosis—hence the name “keto diet.” Once this shift, happens, you will lose weight, but you may also have experience so negative side effects. This is commonly referred to as the keto “flu.”
“If someone with diabetes is [taking insulin or oral type 2 meds in the sulfonylurea or meglitinide class and is] following this diet, they need to know that their blood sugar can drop really quickly, so it’s critical that they check it more frequently,” says Toby Smithson, MS, RDN, CDE, author of Diabetes Meal Planning & Nutrition for Dummies. “Don’t wait for it to happen. Meet with your doctor or diabetes educator in advance so that you can troubleshoot exactly what to do if your blood sugar drops.” If it’s an infrequent occurrence, you may be advised to treat with fast-acting glucose. But frequent lows may require medication adjustments or the addition of more carbs to your eating plan.
Good article. A friend at work is stating this diet and of course being new at it, he is quite the Zealot. I have been into nutrition and exercise for over 40 years (57 years old now). I have tried s few different eating philosophies (I never use the word the word diet. Negative connotation and dieting isn’t good the way most practice it.). Eating Keto style and the logic behind it aren’t too different than some others. And you pointed out many of the misconceptions about cholesterol and triglycerides ect. For about the last 20 plus years I have pretty much followed a “Zone” type diet. 40% carbs, 30% fat, 30% protein. And I always get weird looks at the 30% fat part. Well, I’m 57 with 7% body fat. Not bad for and old guy. I work out and I supplement with protein as I lift weights. It’s worked well. The ratios may be different, but the emphasis on vegetable carbs and good fats are the key to either way to eat. There were only a couple things that kinda struck me as something that made me go hmmmmm. Using the Inuit people isn’t a good example really. They have evolved some different physical features over hundreds of years than we have. And there is no evidence if ketosis occurring in examination. And somehow when you mention eating large amounts of animal fat, just hit me as counterintuitive. It’s a much different fat than an avocado. Finally, and this is just me, I love fruit. True it’s probably less efficient, but its good, sweet, and beats the hell outta donuts for your health. It fulfills the reward need many of us have. I also feel if God put it on the earth naturally, it’s got a place in our food source. I’ve had a philosophy about excersise that’s served me well. What’s the best exercise? The one that you’ll do regularly. Get up and move and find out what works for your own body. It applies to good too. If you feel deprived or for various reasons can’t stay on the supposed best food program, what good is it? But if you stay with more natural and Balanced foods that usually leads to more energy then more and regular excerise. Check in. It looks like it’s been 2 years since you wrote this. I’d live to hear how your doing.
Clinical trials that compare various diets’ outcomes among patients with mental health conditions are sorely lacking. For example, while currently there are 2822 clinical trials registered at Clincaltrials.gov for schizophrenia, none of them are examining the ketogenic diet’s impact on this debilitating chronic condition (three however, are examining gluten-free diets.) Likewise, there are NO ketogenic interventions among 1180 clinical trials for bipolar disorder, 2711 studies for anxiety, and 5370 for depression. (Although there are still a number of trials for these conditions that are looking at “low-fat healthy diets” or “Mediterranean diets” with plenty of fruits, grains and vegetables.)

If you’re wondering why iron is at risk on a meat-based diet, hear me out. Many grain foods provide a considerable amount of iron, because wholegrains naturally contain iron in their inner layer called the ‘germ’. Another reason is that some grain products can have iron added to them during manufacturing. So, once you cut grains out, your iron status could suffer, which can lead to unpleasant symptoms like tiredness and lethargy. It can even compromise your immune system.
No Pete, this is not true. What you have mentioned is based on the seven country epidemiological study done by Ancel Keys in the 1970s. This entire study was based on flawed science. Ancel Keys cherry picked the data that supported his argument for the foundation for his hypothesis. Although this hypothesis was never backed by scientific evidence the mainstream medical system took it as gospel in creating standards for the health professionals.
A great long-term benefit of the ketogenic diet is reduced cravings for sugar and other unhealthy foods. However, you might initially have stronger cravings for carbs during the transition period. This can last anywhere from one to two days to around three weeks. But stick it out! At the end, you’ll be pleased with the reduced, and often eliminated, cravings.

thank you Dr. Jockers for the informative article. I have hypothyroidism from 3 parathyroid cysts being removed along with 80% of my thyroid. It is under control with Levothyroxine and liathyronine. I have been on the keto diet for almost 4 weeks and am still experiencing heart palpatations, dizzyness and low energy. I have been quite strict and feel disappointed. I have Chronic Lymphocytic Leukemia and my oncologist was ok with me going on it. I feel like this diet would help me have more energy and help my overall health. Any advise would be appreciated. thank you, Inika

In some ways, it’s similar to the Atkins diet, which similarly boosts the body’s fat-burning abilities through eating only low-carb foods, along with getting rid of foods high in carbs and sugar. Removing glucose from carbohydrate foods will cause the body to burn fat for energy instead. The major differences between the classic keto and the Atkins diet is the former emphasizes healthier keto fats, less overall protein and no processed meat (such as bacon) while having more research to back up its efficacy.
Mastering Diabetes: Studies conducted in tens of thousands of people over 5+ years indicate that low-carbohydrate diets increase your risk for cardiovascular disease, hemorrhagic stroke, hypertension, atherosclerosis, diabetes mortality, obesity, cancer, and all-cause mortality (premature death). No matter how you slice it, low-carbohydrate diets trick patients and doctors into believing that ketosis is an excellent long-term dietary strategy, when in reality the consequences can be disastrous.

The good news is, if you’re a generally healthy adult, you can probably tolerate the keto diet. “It’s likely appropriate and safe for almost everyone,” says Robert Santos-Prowse, a Clinical Dietitian and the author of The Ketogenic Mediterranean Diet and The Cyclical Ketogenic Diet. “Ketosis is a natural metabolic state that everyone has spent some time in at some point in their lives. It has been proven to be most useful for weight loss and diabetes management, but it could provide benefit for some athletes and also might prove to be useful for many disease states including some cancers and forms of neurodegeneration.”
While there have not been large studies that show the relationship between the ketogenic diet and cancer, we will be publishing a case study about that topic. The author failed to comment that pediatric patients with epilepsy are on the diet for usually about 2 years with no harmful effects. Before the false studies about heart disease and fat, the low carb diet was a respected way to lose weight. Studies into our metabolism show we can use both fat and carbohydrate as fuel. So stepping away from our high carb diet- I am sorry to say that we eat more carbs since the 70s with most of it processed and we now use high fructose corn syrup to sweeten products and we have a wide spread childhood obesity problem. If cholesterol is a concern try plant sterols and stenals to block cholesterol from the receptors in the body. So much more can be said about a keto diet than this article states
The kidneys play an important role in metabolizing protein, and it’s possible that eating too much of the nutrient can have a negative impact on kidney function. While ketogenic diets are supposed to be much higher in fat than they are in protein, many keto eaters make the mistake of loading up on lots of meat, Mancinelli says. The result? You could end up eating way more protein than you actually need.
If you’re wondering about the difference between ketosis and diabetic ketoacidosis, you’re not alone. “The word ketone is scary for most people with type 1 diabetes because they relate ketones to diabetic ketoacidosis,” says Patti Urbanski, MEd, RD, CDE, a certified diabetes educator with St. Luke’s Hospital in Duluth, Minnesota. “But with the ketogenic diet, we’re talking about a much lower level of ketones.”
I am a T2D, finally fully keto starting at the end of March. I am down 28 lbs. My goal is 50, so I am feeling encouraged and fitting into smaller sizes already. In May my A1C was 5.6. This morning, according to a home test kit I purchased from CVS, my A1C is 5. I believe that is fairly accurate based on my blood sugar readings, which are staying well below 100.
The targeted keto diet is popular among athletes and active individuals who live a keto lifestyle but need more carbs. It allots an additional 20-30 grams of carbs immediately before and after workouts to allow for higher-intensity exercise and enhanced recovery. (The total carb count comes to 70-80 grams per day.) The best options include fruit, dairy or grain-based foods, or sports nutrition products. Because the additional carbs are readily burned off, they don't get stored as body fat.

In the present study, a control population on a low fat diet was not included due to the difficulties in recruiting subjects for a control group. However, several studies (63,64) with appropriate control groups that compared the effect of a low fat diet with a low carbohydrate ketogenic diet have recently been published. In this regard, these two recent studies are comparable with the present study. Brehm et al (23) showed that obese women on a low carbohydrate ketogenic diet lost 8.5 kg over six months compared with 4.2 kg lost by those in the low fat diet group (P<0.001). Twenty-two subjects from the low carbohydrate ketogenic diet and 20 subjects from the low fat diet completed the study, with both groups reducing their energy intake by approximately 450 kcal from the baseline level. In another study performed in 132 severely obese subjects for six months (24), there was greater weight loss in the low carbohydrate ketogenic diet group than in the low fat diet group (5.8 kg versus 1.9 kg, P=0.002). Both of these studies support the findings presented in the present paper.
Financial disclosures: There were no conflicts of interest reported except for Dr Bernstein who has received royalties for books on the management of diabetes (which were used by members of the online social media group surveyed in this study). Dr. Hallberg who holds stock options and receives research support from Virta Health, and consulting fees from Atkins. Dr. Rhodes is the site principal investigator in clinical trials for pediatric type 2 diabetes that are sponsored by Merck and AstraZeneca. Dr. Westman has an ownership interest in companies using low-carbohydrate principles, and he receives royalties for books related to low-carbohydrate diets. Dr. Ludwig has received royalties from books on nutrition and obesity; and Dr. Galati is author of Eating Yourself Sick: How to stop obesity, fatty liver, and diabetes from killing you and your family (2018).
It’s not a good idea to include a lot of dairy in a ketogenic diet because the protein in dairy can deactivate Sirtuin, the anti-aging pathway, and create an insulin spike. While butter and ghee (from quality pastured sources) generally don’t cause this effect, high-fat cheeses and heavy creams do. In addition, dairy products can be inflammatory for many people.

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.
I’ve been doing low-carb-high-fat (LCHF) for more than nine years. I’m not diabetic and never was so far as I know, nor was I particularly overweight. I simply became convinced over time that this way of eating is the best way to limit the damage which can be done by a lifetime of exposure to the standard American high-carb, starchy, sugary diet. I love my fatty meat, egg yolks, butter, sour cream, and more. I suppose I am fortunate I never had “carb-cravings”.
Additionally, you may find it difficult to eat adequate calories on a daily basis because fat is so filling. Some people even opt to fast for several hours each day. While this may help with weight loss, your body needs those calories for proper maintenance. Without them, it may turn to burning muscle for energy, and that can accelerate muscle loss.
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