Despite its explosive popularity, there’s a lot of confusion about what the ketogenic (keto) diet really is. “Many people think they’re following a keto diet when they’re really just consuming a low-carbohydrate diet,” says Patti Urbanski, MEd, RD, CDE, a certified diabetes educator with St. Luke’s Hospital in Duluth, Minnesota. “So one person’s ‘keto diet’ may look very different than another’s.”
Here are a few of the most common side effects that I come across when people first start keto. Frequently the issues relate to dehydration or lack of micronutrients (vitamins) in the body. Make sure that you’re drinking enough water (close to a gallon a day) and eating foods with good sources of micronutrients. To read more on micronutrients, click here >
Before starting, ask yourself what is really realistic for you, Mattinson suggests. Then get your doctor’s okay. You may also work with a local registered dietitian nutritionist to limit potential nutrient deficiencies and talk about vitamin supplementation, as you won’t be eating whole grains, dairy, or fruit, and will eliminate many veggies. “A diet that eliminates entire food groups is a red flag to me. This isn’t something to take lightly or dive into headfirst with no medical supervision,” she says.
Wondering what fits into a keto diet — and what doesn’t? “It’s so important to know what foods you’ll be eating before you start, and how to incorporate more fats into your diet,” says Kristen Mancinelli, RD, author of The Ketogenic Diet: A Scientifically Proven Approach to Fast, Healthy Weight Loss, who is based in New York City. We asked her for some guidelines.
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.
One meta-analysis18 incorporating data from 447 participants found that low-carbohydrate diets not only helped individuals lose weight, but also improved their cholesterol. And another meta-analysis,19 citing 17 clinical trials, found that low-carb diets protected against major cardiovascular risk factors. A third study20 including 119 participants found that low-carbohydrate dieters had lower cholesterol than low-fat dieters after one year.
Upon starting the diet, some patients report symptoms like fatigue, headaches, and muscle aches. However, these short-lived symptoms are, in fact, a sign that the diet is working, and the body is switching over from burning glucose as fuel to burning fat. This transition involves upregulating certain enzymes and down-regulating others; it is a profound shift for the human body that can have uncomfortable symptoms. However, these side effect usually last only 3-4 weeks. They can be ameliorated in most cases, by drinking several cups of bouillion broth during the day until the transition is completed.15
A keto diet has shown to improve triglyceride levels and cholesterol levels most associated with arterial buildup. More specifically low-carb, high-fat diets show a dramatic increase in HDL and decrease in LDL particle concentration compared to low-fat diets.3A study in the long-term effects of a ketogenic diet shows a significant reduction in cholesterol levels, body weight, and blood glucose. Read more on keto and cholesterol >

Moreover, the ketogenic diet also reliably raise the “good” HDL-cholesterol, while also improving most other cardiovascular markers, including blood pressure, as this study shows.24 Thus, the overall effect on cholesterol and other markers for heart disease is positive. In some lean hyper-responders, a keto diet will increase LDL particle number, and this effect needs further investigation.


Metagenics offers a wide range of educational opportunities including webinars, group meetings, and seminars as part of our commitment to continuing functional medicine education. Our goal is to give our practitioners further insight to help address their patients’ unique health needs for a higher level of personalized, lifetime wellness care. We have been sharing this ever-growing body of nutritional and lifestyle research for over 25 years.

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.


No deep fryers or air fryers needed for these wings! Forget those greasy chicken wings you’d order at a restaurant and opt-in for these homemade guiltless garlic parmesan wings. You won’t find rancid vegetable oil, gluten or a deep frier here — just avocado oil, healthy pecorino romano and free-range, organic chicken for a twist on an otherwise unhealthy classic.
If you’ve decided to move forward in trying the keto diet, you will want to stick to the parameters of the eating plan. Roughly 60 to 80 percent of your calories will come from fats. That means you’ll eat meats, fats, and oils, and a very limited amount of nonstarchy vegetables, she says. (This is different from a traditional low-carb diet, as even fewer carbs are allowed on the keto diet.)

Around this time, Bernarr Macfadden, an American exponent of physical culture, popularised the use of fasting to restore health. His disciple, the osteopathic physician Dr. Hugh William Conklin of Battle Creek, Michigan, began to treat his epilepsy patients by recommending fasting. Conklin conjectured that epileptic seizures were caused when a toxin, secreted from the Peyer's patches in the intestines, was discharged into the bloodstream. He recommended a fast lasting 18 to 25 days to allow this toxin to dissipate. Conklin probably treated hundreds of epilepsy patients with his "water diet" and boasted of a 90% cure rate in children, falling to 50% in adults. Later analysis of Conklin's case records showed 20% of his patients achieved freedom from seizures and 50% had some improvement.[10]


The keto diet isn’t new, and it’s been around for nearly a century. It was originally developed to treat people with epilepsy. In the 1920s, researchers found that raised levels of ketones in the blood led to fewer epileptic seizures in patients. The keto diet is still used today to treat children with epilepsy who don’t respond well to anti-epileptic drugs.[2]
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 can be heavy on red meat and other fatty, processed, and salty foods that are notoriously unhealthy. What is unhealthy about red meat. We should know that acrilamides, pyrroles in burnt meat (and veges) from BBQ and over-heated cooking inflames the colon. According to Clark H R, PhD ND an inflamed part allows easy entry for the cancer nucleus and cancer complex, to start and fuel a malignancy at that location.
When you eat tons of carbs, your blood sugar is consistently elevated, and then so is insulin. Insulin is a hormone that keeps your blood sugar in check by shuttling the glucose into cells, but when there’s a consistently high amount of insulin, your cells become resistant. This insulin resistance makes it easier to store fat, and chronically high levels of insulin also cause excessive inflammation in the body, which contributes to heart disease, high blood pressure, and potentially type 2 diabetes.

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.


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.
No human population has ever lived in a permanent state of ketosis. Ketogenic diets are dangerous for pregnant women and developing fetuses, and the only human population that has ever subsisted on this dietary pattern advocated by keto diet proponents could only do so because of a genetic mutation that prevents them from going into ketosis. Unfortunately, it has the unintended but unavoidable consequence of reducing the survival prospects of their infants.
Even in endurance sports that don’t require sprinting, ketogenic-style diets are disadvantageous according to a ketogenic diet and exercise article published in Sports Medicine[5]: “a high-fat, low-carbohydrate ketogenic diet may impair exercise performance via reducing the capacity to utilize carbohydrates, which forms a key fuel source for skeletal muscle during intense endurance-type exercise.” The article concluded, “At present there are no data available to suggest that ingestion of ketone bodies during exercise improves athletes’ performance under conditions where evidence-based nutritional strategies are applied appropriately.”
My kidney doctor said that he has never seen anything like that before and wanted to know what I was doing. I told him that I was doing a combination of a ketogenic diet and daily coffee enemas through the training I got in your Keto and Cancer Cleanse online programs. He couldn’t believe his ears. I had to explain what each one of those things were.  

Professional guidance is important in deciding whether or not the ketogenic diet is the right path based on the individual’s health history and goals, and it's also necessary to routinely monitor ketone levels in the body while on the diet. At Metagenics, we offer a number of resources to help support the ketogenic journey along with several convenient ketogenic supplementation options to help bring convenience and variety to ketogenic living.
The other nutritional remedy for T2 diabetes is carbohydrate restriction. In a large, ongoing university-based study, 60% of patients with Type 2 diabetes reversed their diagnosis of diabetes after just one year on a ketogenic diet, supplemented by support via a mobile phone app.11 On this protocol, 94% of participants reduced or eliminated their need for insulin medications while improving the vast majority of cardiovascular risk factors.12
There are three essential components of all food: fats, carbohydrates and protein. The ketogenic diet is a carefully prescribed ratio of fats to carbohydrates and protein. This ratio causes the body to convert fat into substances called ketone bodies (thus the name). These ketones are then used for fuel in many cells of the body, including the brain. When this happens, the brain goes into a higher energy state and is better able to protect itself against seizures.
The ketogenic diet achieved national media exposure in the US in October 1994, when NBC's Dateline television programme reported the case of Charlie Abrahams, son of Hollywood producer Jim Abrahams. The two-year-old suffered from epilepsy that had remained uncontrolled by mainstream and alternative therapies. Abrahams discovered a reference to the ketogenic diet in an epilepsy guide for parents and brought Charlie to John M. Freeman at Johns Hopkins Hospital, which had continued to offer the therapy. Under the diet, Charlie's epilepsy was rapidly controlled and his developmental progress resumed. This inspired Abrahams to create the Charlie Foundation to promote the diet and fund research.[10] A multicentre prospective study began in 1994, the results were presented to the American Epilepsy Society in 1996 and were published[17] in 1998. There followed an explosion of scientific interest in the diet. In 1997, Abrahams produced a TV movie, ...First Do No Harm, starring Meryl Streep, in which a young boy's intractable epilepsy is successfully treated by the ketogenic diet.[1]
The ketogenic diet achieved national media exposure in the US in October 1994, when NBC's Dateline television programme reported the case of Charlie Abrahams, son of Hollywood producer Jim Abrahams. The two-year-old suffered from epilepsy that had remained uncontrolled by mainstream and alternative therapies. Abrahams discovered a reference to the ketogenic diet in an epilepsy guide for parents and brought Charlie to John M. Freeman at Johns Hopkins Hospital, which had continued to offer the therapy. Under the diet, Charlie's epilepsy was rapidly controlled and his developmental progress resumed. This inspired Abrahams to create the Charlie Foundation to promote the diet and fund research.[10] A multicentre prospective study began in 1994, the results were presented to the American Epilepsy Society in 1996 and were published[17] in 1998. There followed an explosion of scientific interest in the diet. In 1997, Abrahams produced a TV movie, ...First Do No Harm, starring Meryl Streep, in which a young boy's intractable epilepsy is successfully treated by the ketogenic diet.[1]
Potatoes and gravy are total comfort food — and luckily, there’s a keto version. These are made with cauliflower, which is quite low-carb, particularly when compared to potatoes. Made with cream, butter, rosemary and parmesan, this mash is creamy, full of flavor and smooth. You’ll finish it all off with a stock-based gravy, that would be perfect on a roast, too.
Normal dietary fat contains mostly long-chain triglycerides (LCTs). Medium-chain triglycerides (MCTs) are more ketogenic than LCTs because they generate more ketones per unit of energy when metabolised. Their use allows for a diet with a lower proportion of fat and a greater proportion of protein and carbohydrate,[18] leading to more food choices and larger portion sizes.[4] The original MCT diet developed by Peter Huttenlocher in the 1970s derived 60% of its calories from MCT oil.[15] Consuming that quantity of MCT oil caused abdominal cramps, diarrhea, and vomiting in some children. A figure of 45% is regarded as a balance between achieving good ketosis and minimising gastrointestinal complaints. The classical and modified MCT ketogenic diets are equally effective and differences in tolerability are not statistically significant.[9] The MCT diet is less popular in the United States; MCT oil is more expensive than other dietary fats and is not covered by insurance companies.[18]
The other nutritional remedy for T2 diabetes is carbohydrate restriction. In a large, ongoing university-based study, 60% of patients with Type 2 diabetes reversed their diagnosis of diabetes after just one year on a ketogenic diet, supplemented by support via a mobile phone app.11 On this protocol, 94% of participants reduced or eliminated their need for insulin medications while improving the vast majority of cardiovascular risk factors.12
Professional guidance is important in deciding whether or not the ketogenic diet is the right path based on the individual’s health history and goals, and it's also necessary to routinely monitor ketone levels in the body while on the diet. At Metagenics, we offer a number of resources to help support the ketogenic journey along with several convenient ketogenic supplementation options to help bring convenience and variety to ketogenic living.
The day before admission to hospital, the proportion of carbohydrate in the diet may be decreased and the patient begins fasting after his or her evening meal.[19] On admission, only calorie- and caffeine-free fluids[37] are allowed until dinner, which consists of "eggnog"[Note 8] restricted to one-third of the typical calories for a meal. The following breakfast and lunch are similar, and on the second day, the "eggnog" dinner is increased to two-thirds of a typical meal's caloric content. By the third day, dinner contains the full calorie quota and is a standard ketogenic meal (not "eggnog"). After a ketogenic breakfast on the fourth day, the patient is discharged. Where possible, the patient's current medicines are changed to carbohydrate-free formulations.[19]
Getting control of your diet is the first and most important step towards lasting health and weight loss. Low carb recipes like these will give you a good blueprint to move forward with permanent changes to the way you eat that will improve your life and health. When filled with healthy, whole foods that are low in carbs and prepared deliciously, the keto diet is an amazing way to create a lasting, positive difference in your life!
I tried the keto diet a couple years ago and about 6 weeks in of following it closely I started having significant episodes of lightheadedness and anxiety like symptoms. The coach I was working with said it was keto flu so I continued on the diet for a couple more weeks but it was making life difficult so I stopped. Now every time I try to go low carb the symptoms come back. Sometimes I wonder if it’s just anxiety response or all in my head. I would love to eat low carb but haven’t ever been able to figure out why this happens. I read somewhere that keto can be harder for women’s bodies and affect their adrenal glands. Would this increase anxiety symptoms.
Bulk buy and cook. If you’re someone who doesn’t like to spend a lot of time in the kitchen, this is the best of both worlds. Buying your food at bulk (specifically from wholesalers) can reduce the cost per pound tremendously. Plus, you can make ahead food (bulk cook chicken thighs for pre-made meat, or cook entire meals) that are used as leftovers, so you spend less time cooking.
All of our diets are developed with each individual child in mind. We focus on what the child likes to eat and try as much as possible to incorporate their favorite foods into their diets, and many children actually enjoy their keto food. Even if your child is already on a special diet due to allergies or food intolerances, our team can still incorporate these special needs into your child's ketogenic diet.
Even when exercising at a submaximal level (for example, biking at a moderate speed), heart rate and adrenaline levels rise more when people are eating a high-fat, low-carbohydrate diet[4] vs. a high-carbohydrate, low-fat diet. This results in those on the high fat diet perceiving that they are working harder to achieve the same pace as the high-carbers, and they have much more difficulty speeding up their pace in sprints or climbs.
When you’re eating the foods that get you there (more on that in a minute), your body can enter a state of ketosis in one to three days, she adds. During the diet, the majority of calories you consume come from fat, with a little protein and very little carbohydrates. Ketosis also happens if you eat a very low-calorie diet — think doctor-supervised, only when medically recommended diets of 600 to 800 total calories.
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