The ketogenic or “keto” diet is a low-carbohydrate, fat-rich eating plan that has been used for centuries to treat specific medical conditions. In the 19th century, the ketogenic diet was commonly used to help control diabetes. In 1920 it was introduced as an effective treatment for epilepsy in children in whom medication was ineffective. The ketogenic diet has also been tested and used in closely monitored settings for cancer, diabetes, polycystic ovary syndrome, and Alzheimer’s disease.


What do LeBron James, Tim McGraw, and Halle Berry have in common? They all attribute their fab physiques to the keto diet plan, a high-fat, low-carb diet that is currently blowing up the internet. According to Google Trends, the keto diet peaked in popularity this week — and shows no signs of stopping. There are 4 million #keto posts on Instagram and more than 69 million keto diet recipes on Pinterest.[1] As the ketogenic diet goes mainstream, some news outlets have described it as another unhealthy celebrity fad diet. Here’s what you need to know about the keto lifestyle — and how the Bulletproof Diet does it one better.
Prolonged ketosis and large buildups of ketones can be dangerous, but VLCDs intentionally bring on mild ketosis. At a certain level, ketosis brings on desirable changes that facilitate safe weight loss and keep important body processes working properly while getting so few calories. When your body is using fat for energy, you may be losing weight, but your brain can be starving because it primarily uses glucose, or carbohydrates, for energy. However, ketones can cross the blood-brain barrier and supply most of your brain's energy needs, according to Wim Saris, a researcher writing in the November 2001 "Obesity Research" journal. Without ketones fulfilling this role, your body will begin to break down amino acids, your protein building blocks, into blood sugar. This can cause you to lose lean muscle mass while on the VLCD.
Psychological well-being and hunger and food control are two relevant factors involved in the success of weight-loss therapy in treating obesity. Thus, this study aims to evaluate food and alcohol cravings, physical and sexual activity, sleep, and life quality (QoL) in obese patients following a very low-calorie ketogenic (VLCK) diet, as well as the role of weight lost and ketosis on these parameters. A battery of psychological test was performed in twenty obese patients (12 females, 47.2 ± 10.2 year and BMI of 35.5 ± 4.4) through the course of a 4-month VLCK diet on four subsequent visits: baseline, maximum ketosis, reduced ketosis, and endpoint. Each subject acted as their own control. Relevantly, the dietary-induced changes in body composition (7.7 units of BMI lost, 18 kg of fat mass (1.2 kg of visceral fat mass)) were associated with a statistically significant improvement in food craving scores, physical activity, sleepiness, and female sexual function. Overall, these results also translated in a notable enhancement in QoL of the treated obese patients. Therefore, the rapid and sustained weight and fat mass (FM) loss induced by the VLCK diet is associated with good food control and improvements in the psychological well-being parameters in obese subjects, which could contribute to the long-term success of this therapy.
Several recent studies indicate that a low-carbohydrate diet is effective at improving glycemia. A few studies have shown that in non-diabetic individuals, low-carbohydrate diets were more effective than higher carbohydrate diets at improving fasting serum glucose [13,14] and insulin [6,14-16], and at improving insulin sensitivity as measured by the homeostasis model [6]. One of these studies also included diabetic patients and noted a comparative improvement in hemoglobin A1c after 6 months (low fat diet: 0.0 ± 1.0%; low carbohydrate diet: -0.6 ± 1.2%, p = 0.06) [6] and 12 months (low fat diet: -0.1 ± 1.6%; low carbohydrate diet: -0.7 ± 1.0%, p = 0.019) duration [5]. In a 5-week crossover feeding study, 8 men with type 2 diabetes had greater improvement in fasting glucose, 24-hour glucose area-under-the-curve (AUC), 24-hour insulin AUC, and glycohemoglobin while on the low-carbohydrate diet than when on a eucaloric low-fat diet [7]. In a 14-day inpatient feeding study, 10 participants with type 2 diabetes experienced improvements in hemoglobin A1c and insulin sensitivity as measured by the euglycemic hyperinsulinemic clamp method [8]. Hemoglobin A1c also improved in an outpatient study of 16 participants who followed a 20% carbohydrate diet for 24 weeks [9].

It's not the easiest plan to follow, but the theory of ketosis as a possible prevention against disease is gaining attention from cancer specialists. Tumor immunologist Dr. Patrick Hwu, one of the leading cancer specialists in the U.S., has followed the keto diet for four years, although he prefers to call it the fat-burning metabolism diet, or fat-burning diet. More research is needed to prove its benefits, but Hwu, the head of cancer medicine at MD Anderson in Houston, believes in it after seeing improvements in his own health.
Though technically a fruit, avocados offer a rich source of heart-healthy monounsaturated fatty acids (MUFAs). They're also packed with fiber to bolster digestive health. One-half of an avocado contains 161 calories, 2 grams (g) of protein, 15 g of fat, 9 g of total carbs, and 7 g of fiber (bringing it to 2 g of net carbs), notes the U.S. Department of Agriculture (USDA).
“I have been a supporter of a low-carb lifestyle that includes intermittent fasting for myself and my patients for years. I am part of our health systems Medicine Residency program. I teach physicians-in-training and medical staff to utilize low-carb and keto dieting to improve the health of their patients and reduce their need for medications. Diet Doctor is an excellent resource for patients and physicians to help patients help themselves to promote a healthy lifestyle.”
On a “strict” (standard) keto diet, fats typically provides about 70 percent to 80 percent of total daily calories, protein about 15 percent to 20 percent, and carbohydrates just around 5 percent. However, a more “moderate” approach to the keto diet is also a good option for many people that can allow for an easier transition into very low-carb eating and more flexibility (more on these types of plans below).
Participants met with researchers 10 times over a four-month period. During 4 of the 10 visits, researchers analyzed participants’ blood and body fat for changes in body weight, hormones, ketone bodies (which are produced during ketosis), and muscle losses. After 60 to 90 days, participants were gradually taken off ketosis and placed on a low-calorie diet consisting of between 800 and 1,500 calories per day, and then a maintenance diet consisting of 1,500 and 2,000 calories, depending on the participant. Out of the 20 participants enrolled in the study, 12 completed the regimen and lost about 44.5 pounds each.
In order to transition and remain in this state, aiming for about 30–50 net grams is typically the recommended amount of total carbs to start with. This is considered a more moderate or flexible approach but can be less overwhelming to begin with. Once you’re more accustomed to “eating keto,” you can choose to lower carbs even more if you’d like (perhaps only from time to time), down to about 20 grams of net carbs daily. This is considered the standard, “strict” amount that many keto dieters aim to adhere to for best results, but remember that everyone is a bit different.
Minerals/Electrolytes: Adopting a ketogenic diet will change the way your body uses (and loses) certain minerals. Not replacing these minerals can lead to symptoms of the “keto flu” such as lightheadedness, headaches, constipation, muscle cramps and fatigue. Refer to this article for tips on how to replace common minerals such as sodium, potassium, magnesium and calcium.
In this single-arm, 4-month diet intervention, an LCKD resulted in significant improvement of glycemia, as measured by fasting glucose and hemoglobin A1c, in patients with type 2 diabetes. More importantly, this improvement was observed while diabetes medications were reduced or discontinued in 17 of the 21 participants, and were not changed in the remaining 4 participants. Participants also experienced reductions in body weight, waist circumference, and percent body fat but these improvements were moderate and did not predict the change in hemoglobin A1c in regression analyses.
Formulating the diet properly: The ketogenic diet allows for a lot of flexibility when it comes to the types of fats you consume. However, if most of your calories are coming from beef and bacon, fibre is left in the lurch. And when fibre is left in the lurch, your gut suffers. Don’t care about gut health? You should. An unhealthy gut is a major obstacle to fat loss. Supplement with probiotics to ensure your gut stays in good shape. 

According to one hypothesis, low-carb diets have a distinct “metabolic advantage” over diets with higher carbohydrate content when the amount of calories consumed are the same.3 This metabolic advantage is essentially an increase in the expenditure of energy (calories) on the low-carb diet. Factors that may account for this higher rate of calorie burning include:
If you’re looking to get a jump start on your health and fitness goals this year, you may be thinking about trying the ketogenic diet. Maybe you’ve heard the phrase before — it’s a huge diet buzzword — but aren’t sure what it means. Here’s a primer: The ketogenic diet is an eating plan that drives your body into ketosis, a state where the body uses fat as a primary fuel source (instead of carbohydrates), says Stacey Mattinson, RDN, who is based in Austin, Texas.
“I am amazed at what a low-carbohydrate diet can do in real life and in my oncology practice. I see many cases of difficult to treat cancers, and know full-well the limitations of conventional chemotherapy. When patients ask about the ketogenic diet and cancer, I point out our recently concluded clinical trial that showed the ketogenic diet to be safe in advanced cancer patients and possibly beneficial in improving quality of life and survival. The diet, together with regular cancer treatment, could be a win-win combination. Diet Doctor is a fabulous website, chock full of information!”
When you eat foods high in carbohydrates and fat, your body naturally produces glucose. Carbohydrates are the easiest thing for the body to process, and therefore it will use them first – resulting in the excess fats to be stored immediately. In turn, this causes weight gain and health problems that are associated with high fat, high carbohydrate diets (NOT keto).
Because people with type 2 diabetes are at an increased risk for cardiovascular disease, there’s a specific concern that the saturated fat in the diet may drive up LDL, or “bad,” cholesterol levels, and further increase the odds of heart problems. If you have type 2 diabetes, talk to your doctor before attempting a ketogenic diet. They may recommend a different weight-loss diet for you, like a reduced-calorie diet, to manage diabetes. Those with epilepsy should also consult their doctor before using this as part of their treatment plan.
We in Broxtowe constituency have to put up with this undemocratic politician daily. To call her duplicitous is a huge understatement. ..... And try getting a reply from her over other issues. All you get is a cut and paste general reply. She's clearly far too busy doing the rounds of radio, TV and other interviews for which she presumably takes fees rather than doing the job she's paid for as an MP.
“At the Duke Diet and Fitness Center, our residential clients can choose from three levels of carb intake that happen to be aligned with the Diet Doctor’s levels of liberal low-carb, moderate low-carb and keto low-carb. The alignment is not by chance, however. It’s because we have separately come to the same conclusions after carefully and objectively reviewing the evidence and gathering information from experienced clinicians and patients. The Diet Doctor website is very unique in that regard, and a great resource for our patients!”

When ketone bodies accumulate in the blood, this is called ketosis. Healthy individuals naturally experience mild ketosis during periods of fasting (e.g., sleeping overnight) and very strenuous exercise. Proponents of the ketogenic diet state that if the diet is carefully followed, blood levels of ketones should not reach a harmful level (known as “ketoacidosis”) as the brain will use ketones for fuel, and healthy individuals will typically produce enough insulin to prevent excessive ketones from forming. [2] How soon ketosis happens and the number of ketone bodies that accumulate in the blood is variable from person to person and depends on factors such as body fat percentage and resting metabolic rate. [3]

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The average daily goal for keto is 20 grams of net carbs. Net carbs are the total carbs in a given serving of food, minus the carbohydrates that are supplied by fiber. You’ll find carb grams quickly add up, even when you’re choosing the best low-carb foods, like spinach and avocado. Keeping your body in a quasi-keto state can be hard on you, warns Santo: “This will leave you feeling sluggish, foggy, and discouraged,” he says. “It will most likely cause a weight plateau, and maybe even weight gain.” Here’s what it’s really like to be on a keto diet.
Essential fatty acids (the omegas) provide core functions to the human body, but they are often times out of balance when on a standard diet. On keto, with a little bit of preparation, your omega fatty acids are easily manageable. If you want to know more about essential fatty acids, omegas, and how they interact with our body on a ketogenic diet, you can read more here >
HDL is still low and stuck on 45 even after hoping strongly with more healthy saturated fats organic bone broth from lamb bones, etc. LDL way up 170 and triglycerides a a record high of 170, Non HDL choleseterol at 203. Kinda surprizd I cannot more that HDL number aftyer all the keto stuff. And unsure why the LDL has exploded since stress has always been with me these last 9 years.
You can have a completely smooth transition into ketosis, or…not. While your body is adapting to using ketones as your new fuel source, you may experience a range of uncomfortable short-term symptoms. These symptoms are referred to as “the keto flu.” Low-sodium levels are often to blame for symptoms keto flu, since the kidneys secrete more sodium when you’re in ketosis, says Volek. A few side effects:
Are you tracking your calorie intake? Healthy fats also have higher calories and can put you at or over your bodies calorie requirement. Calculate the calories that you have been eating over the past while and then check how many calories you should actually be taking in. If you want to lose weight you have to be in calorie deficit regardless of whether you are in ketosis or not.
Hi Barb, That can definitely be it. Losing when you are close to goal can be more difficult. It could also be that your body’s healthy weight is a little higher than what you’d like – which doesn’t mean you can’t lose, but makes it more difficult. If just eating Keto foods isn’t working, double check the macros for your weight and see if the amount you’re eating needs to be adjusted. You’ll find more help and support in our support group here.

“Through my 31 years in primary care, I have witnessed the growing waistlines and blood sugar levels of my patients. Seeing that the “eat less, move more” advice was failing them, I moved to a low-carb, high-fat approach eight years ago. This has produced great results in my patients. I am able to manage many medical issues without resorting to medications. This new approach has revitalized my practice. I feel like I can finally really help my patients.”

A ketogenic diet may be an option for some people who have had difficulty losing weight with other methods.  The exact ratio of fat, carbohydrate, and protein that is needed to achieve health benefits will vary among individuals due to their genetic makeup and body composition. Therefore, if one chooses to start a ketogenic diet, it is recommended to consult with one’s physician and a dietitian to closely monitor any biochemical changes after starting the regimen, and to create a meal plan that is tailored to one’s existing health conditions and to prevent nutritional deficiencies or other health complications. A dietitian may also provide guidance on reintroducing carbohydrates once weight loss is achieved.
Some fruits may contain relatively high concentrations of sugar, most are largely water and not particularly calorie-dense. Thus, in absolute terms, even sweet fruits and berries do not represent a significant source of carbohydrates in their natural form, and also typically contain a good deal of fiber which attenuates the absorption of sugar in the gut.[20]
Keep up electrolytes. The major electrolytes in our bodies are sodium, potassium and magnesium. Because a low carb diet (especially a keto diet!) reduces the amount of water you store, this can flush out electrolytes and make you feel sick (called “keto flu”). This is temporary, but you can avoid or eliminate it by salting your food liberally, drinking broth (especially bone broth), and eating pickled vegetables. Some people also choose to take supplements for electrolytes, but it’s best to first consult a doctor that understands and supports keto/low carb lifestyles.
Several studies have investigated the potential of LCD or KD on weight loss. For example, Brinkworth et al. (2) compared one year of low-fat (LF) vs. LCD diet in adults with abdominal obesity. Subjects were randomly assigned and diets were isocaloric, with moderate energy restriction. Both groups realized significant weight loss, however, there was no significant difference between groups, suggesting that a LCD was equally effective as a LF diet.
The inclusion criteria were age 18 to 65 years, body mass index (BMI) ≥ 30 kg/m2, stable body weight in the previous 3 months, a desire to lose weight, and a history of failed dietary efforts. The main exclusion criteria were thyroid alteration, diabetes mellitus, obesity induced by other endocrine disorders or by drugs, and participation in any active weight-loss program in the previous 3 months. In addition, those patients with previous bariatric surgery, known or suspected abuse of narcotics or alcohol, severe depression or any other psychiatric disease, severe hepatic insufficiency, any type of renal insufficiency or gouts episodes, nephrolithiasis, neoplasia, previous events of cardiovascular or cerebrovascular disease, uncontrolled hypertension, orthostatic hypotension, and hydroelectrolytic or electrocardiographic alterations were excluded. Females who were pregnant, breastfeeding, or intending to become pregnant and those with child-bearing potential and not using adequate contraceptive methods were also excluded. Apart from obesity and metabolic syndrome, participants were generally healthy individuals. Under these conditions, 20 obese patients were included in this study.
Regarding higher-carbohydrate diets, 20 studies reported higher energy expenditure, and this increase in energy expenditure was statistically significant in 14 of those studies. Overall, the evidence suggests that the carbohydrate and fat content of the diet has little impact on energy expenditure. In other words, low-carb diets do not have a significant metabolic advantage like many insulin theory proponents believe.
In part, keto diet weight loss is a real thing because high-fat, low-carb diets can both help diminish hunger and boost weight loss through their hormonal effects. As described above, when we eat very little foods that supply us with carbohydrates, we release less insulin. With lower insulin levels, the body doesn’t store extra energy in the form of fat for later use, and instead is able to reach into existing fat stores for energy.
Yes, you'll lose weight but only because you're consuming fewer calories. There's no real magic to the keto diet. The weight-loss equation remains the same: You lose weight when you consume fewer calories than you use each day. You're not burning more fat than other diets, or at a faster rate. On the keto diet, you eat high-fat meals with protein, which keeps you feeling full for longer and cuts down on your overall eating throughout the day.
These affect your brain and spine, as well as the nerves that link them together. Epilepsy is one, but others may be helped by a ketogenic diet as well, including Alzheimer’s disease, Parkinson’s disease, and sleep disorders. Scientists aren’t sure why, but it may be that the ketones your body makes when it breaks down fat for energy help protect your brain cells from damage.
Hi Kim, there are several factors for developing autoimmune diseases, including Hashimoto's. I believe that in my case it was a combination of high-carb & low-calorie dieting that have contributed to it. I found out by accident because I went for allergy testing where they discovered I had thyroid antibodies. You should definitely avoid following a low-calorie diet (1000 kcal is not enough). Have a look at this tool: KetoDiet Buddy - Easy Macro Calculator for the Ketogenic Diet
An important strength of this study was the use of 3 different techniques for determining body composition in different settings, i.e., obesity and no ketosis, marked reduction in body weight with high ketosis, and finally, substantial reduction in body weight without ketosis. The tight control of adherence by daily measurement of B-OHB is another relevant strength of this work. A potential limitation of our study could be the sample size; however, because each subject underwent 4 evaluations, enabling each individual subject’s own results to be compared, this adds statistical power to the study and a real difference between the experimental points.
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)?
But there is evidence that low-carb diets may increase metabolism, according to a paper published November 14 in BMJ. Researchers found that overweight adults who lowered carbohydrates and added more fat into their diets burned about 250 calories more each day than people on high-carb, low-fat diets. The study is impressive because it's the largest, most expensive, and controlled study of its kind.
According to one hypothesis, low-carb diets have a distinct “metabolic advantage” over diets with higher carbohydrate content when the amount of calories consumed are the same.3 This metabolic advantage is essentially an increase in the expenditure of energy (calories) on the low-carb diet. Factors that may account for this higher rate of calorie burning include:
Twenty calories a day times the 365 days in a year comes to a little more than seven thousand calories stored as fat every year—two pounds of excess fat. If it were true that our adiposity is determined by calories-in/calories-out, then this is one implication: you only need to overeat, on average, by twenty calories a day to gain fifty extra pounds of fat in twenty years. You need only to rein yourself in by this amount—undereat by twenty calories a day—to undo it. Twenty calories is less than a single bite of a McDonald’s hamburger or a croissant. It’s less than two ounces of Coke or Pepsi or the typical beer. Less than three potato chips. Maybe three small bites of an apple. In short, not very much at all. Twenty calories is less than 1 percent of the daily caloric intake that the U.S. National Academy of Sciences has recommended for a middle-aged woman whose idea of regular physical activity is cooking and sewing; it’s less than half a percent of the daily quota of calories recommended for an equally sedentary middle-aged man. That it’s such an insignificant amount is what makes it so telling about the calories-in/calories-out idea.
Yes, you'll lose weight but only because you're consuming fewer calories. There's no real magic to the keto diet. The weight-loss equation remains the same: You lose weight when you consume fewer calories than you use each day. You're not burning more fat than other diets, or at a faster rate. On the keto diet, you eat high-fat meals with protein, which keeps you feeling full for longer and cuts down on your overall eating throughout the day.
Essential fatty acids (the omegas) provide core functions to the human body, but they are often times out of balance when on a standard diet. On keto, with a little bit of preparation, your omega fatty acids are easily manageable. If you want to know more about essential fatty acids, omegas, and how they interact with our body on a ketogenic diet, you can read more here >
Essentially, the keto diet for beginners works by “tricking” the body into acting as if its fasting (while reaping intermittent fasting benefits), through a strict elimination of glucose that is found in carbohydrate foods. Today the standard keto diet goes by several different names, including the “low-carbohydrate” or “very-low-carbohydrate ketogenic diet”(LCKD or VLCKD for short).
The keto diet also appears to help induce autophagy, which helps clear damaged cells from the body, including senescent cells that serve no functional purpose but still linger inside tissues and organs. In animal studies when rats are put on the ketogenic diet, autophagic pathways are created that reduce brain injury during and after seizures. (21)
The keto diet is known for helping people lose a few pounds very quickly, says Becky Kerkenbush, RD, a clinical dietitian at Watertown Regional Medical Center. Carbs hold on to more water than protein or fat, so when you stop eating them, your body releases all that extra H2O by making you pee more. As a result, the scale might read a few pounds lower, and you may look a bit leaner.
Make things yourself. While it’s extremely convenient to buy most things pre-made or pre-cooked, it always adds to the price per pound on items. Try prepping veggies ahead of time instead of buying pre-cut ones. Try making your stew meat from a chuck roast. Or, simply try to make your mayo and salad dressings at home. The simplest of things can work to cut down on your overall grocery shopping.
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