The most common and relatively minor short-term side effects of ketogenic diet include a collection of symptoms like nausea, vomiting, headache, fatigue, dizziness, insomnia, difficulty in exercise tolerance, and constipation, sometimes referred to as keto flu. These symptoms resolve in a few days to few weeks. Ensuring adequate fluid and electrolyte intake can help counter some of these symptoms. Long-term adverse effects include hepatic steatosis, hypoproteinemia, kidney stones, and vitamin and mineral deficiencies.
“As an American board-certified endocrinologist who moved back to Mumbai, I saw India’s diabetes epidemic and dogma through a different lens. Low carb plus intermittent fasting has proven very effective in the reversal of insulin resistance, fatty liver, PCOS, reduced fertility, obesity, metabolic syndrome, hypertension and even early diabetic neuropathy and nephropathy. I conduct Diabetes Self-Management classes every month while looking at the whole lifestyle: stress, sleep, exercise, mindfulness, self-care and nutrition. This works even in India’s predominantly vegetarian culture! I often refer patients to DietDoctor for low-carb recipes and FAQ’s.”
In the absence of CHO, however, the body must shift to fat as the primary energy source. In this case, the body catabolizes stored triglycerides, which exist in abundance in even the leanest individual. In effect, the KD provokes a physiological stimulus, i.e., CHO restriction, that mimics starvation. Due to the limited ability to store or produce CHO during periods of starvation, the body thus switches to ketogenesis, the production of ketone bodies as a primary fuel source (3).
Muscular strength was measured with a Jamar handgrip dynamometer (Lafayette Instruments, Lafayette, IN). After a brief demonstration and verbal instructions, the test was performed in the standing position with the wrist in the neutral position and the elbow flexed to 90 degrees. Patients were given verbal encouragement to squeeze as hard as possible and to apply maximal effort for at least 3 seconds. Two trials were allowed in the dominant limb, and the highest score was recorded as peak grip strength (kg). Considering possible influences on the muscular strength of changes in body composition, handgrip strength (HG) was divided by appendicular lean mass (ALM) determined by DXA (HG/ALM) and by appendicular soft lean mass (ASLM) determined by MF-BIA (HG/ASLM).
All anthropometric measurements were undertaken after an overnight fast (8 to 10 h), under resting conditions, in duplicate, and performed by well-trained health workers. Participants’ body weights were measured to the nearest 0.1 kg on the same calibrated electronic device (Seca 220 scale, Medical Resources, EPI Inc. (Lewis Center, OH, USA) in underwear and without shoes. BMI was calculated by dividing body weight in kilograms by the square of height in meters; BMI = weight (kg)/height2 (m).
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.
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.
Just because you're getting headaches doesn't mean your diet is the culprit. Berkeley University Health Services reports that headaches may also be a sign of muscle tightening in your neck triggered by fatigue, depression or emotional stress. However, if you're experiencing chronic headaches, you're not losing more than 2 pounds weekly and you're drinking plenty of water, it may be time to talk with your doctor. Although headaches can occur while dieting, chronic headaches that don't subside may be a sign of a more serious medical condition.
First, I want to thank you for all of your dedication and work in providing this site. The difficulty of maintaining a healthy weight is a big problem for so many people. My personal question & issue in staying on Keto is my craving for fresh fruit. This a.m I had a large fresh peach along with my “Bullet Proof” coffee. Have I now sabotaged today’s Keto eating?
The weight-loss program has five steps and adheres to the most recent guidelines of the 2015 EFSA on total carbohydrate intake [22]. The first three steps consist of a VLCK diet (600–800 kcal/day), low in carbohydrates (<50 g daily from vegetables), and lipids (only 10 g of olive oil per day). The amount of high biological-value proteins ranged between 0.8 and 1.2 g per each kg of ideal body weight to ensure that patients were meeting their minimum body requirements and to prevent the loss of lean mass. In step 1, the patients ate high-biological-value protein preparations five times a day and vegetables with low glycemic indexes. In step 2, one of the protein servings was substituted with a natural protein (e.g., meat or fish) either at lunch or at dinner. In step 3, a second serving of low-fat natural protein was substituted for the second serving of biological protein preparation. Throughout these ketogenic phases, supplements of vitamins and minerals, such as K, Na, Mg, Ca, and omega-3 fatty acids, were provided in accordance with international recommendations [23]. These three steps were maintained until the patient lost the target amount of weight, ideally 80%. Hence, the ketogenic steps were variable in time depending on the individual and the weight-loss target. The total ketosis state lasted for 60–90 days only.
A lot of people take their macros as a “set in stone” type of thing. You shouldn’t worry about hitting the mark every single day to the dot. If you’re a few calories over some days, a few calories under on others – it’s fine. Everything will even itself out in the end. It’s all about a long term plan that can work for you, and not the other way around.
You’re ok with not so fast results and can remain disciplined.Every weight loss management plan needs an amount of sacrifice as well as a compromise from the dieter. But the ketosis approach may be one of the most challenging because it will change the most sacred of all eating routines among Western cultures: enjoying a full-dish meal. It's certainly no picnic, but the procedure can be done simpler having the right products and program, and the results can be spectacular. 

Take a multivitamin. “Because you are removing grains, the majority of fruit, some vegetables, and a significant amount of dairy from your menu, a multivitamin is good insurance against any micronutrient deficiencies,” says Jadin. Depending on what your individual overall diet looks like, Jadin says you might also need to add a calcium, vitamin D, and potassium supplement.
I have been on a keto diet for over a year. I lost 60 pounds and got off five different meds and a shot in the stomach for the last 25 years. Fasting sugar under 150 was considered good control. A1C was usually around 7. Now sugars are rarely over 80 and A1C is 5.4. THEN I PLATEAUED AND EVEN GAINED BACK 10 pounds. Little did I know I have been shooting myself in the foot. It didn't help that I quit a job that required seven miles of vigorous walking each day, but I begin my day with a big glass of half and half. I didn't realize I was adding 16-20g hidden carbs over my 25g allotment. I am switching to making my own with heavy whip cream and almond milk. That drops carb count to 6.4g per cup.
A recent systemic review and meta-analysis of randomized controlled trials comparing the long-term effects (greater than 1 year) of dietary interventions on weight loss showed no sound evidence for recommending low-fat diets. In fact, low-carbohydrate diets led to significantly greater weight loss compared to low-fat interventions. It was observed that a carbohydrate-restricted diet is better than a low-fat diet for retaining an individual’s BMR. In other words, the quality of calories consumed may affect the number of calories burned. BMR dropped by more than 400 kcal/day on a low-fat diet when compared to a very low-carb diet.
^ Hu T, Mills KT, Yao L, Demanelis K, Eloustaz M, Yancy WS, Kelly TN, He J, Bazzano LA (October 2012). "Effects of low-carbohydrate diets versus low-fat diets on metabolic risk factors: a meta-analysis of randomized controlled clinical trials". American Journal of Epidemiology. 176 Suppl 7 (Suppl 7): S44–54. doi:10.1093/aje/kws264. PMC 3530364. PMID 23035144.
“As a pediatrician practicing for the past 24 years, I spend most of my clinical time caring for children with chronic behavioral, developmental, psychological or metabolic conditions (ADHD, depression, anxiety, OCD, Tourette’s Syndrome, autism, autoimmune disease, obesity, NAFLD, etc.). A well-planned, low-carbohydrate (and in many cases ketogenic) nutrition plan is a very powerful tool that I use with my patients to address both physical and mental health. I so appreciate Diet Doctor and reference it frequently for my patients as the best resource for this topic. This site is commercial free, well-supported, referenced and frequently updated.”
Dr. Josh Axe, DNM, DC, CNS, is a doctor of natural medicine, clinical nutritionist and author with a passion to help people get well using food as medicine. He’s the author of the books “Eat Dirt: Why Leaky Gut May Be the Root Cause of Your Health Problems,” “Essential Oils: Ancient Medicine” and the upcoming “Keto Diet: Your 30-Day Plan to Lose Weight, Balance Hormones, Boost Brain Health, and Reverse Disease” (February 2019, published by Little, Brown Spark). He’s a co-founder of Ancient Nutrition, a health company where the mission is to restore health, strength and vitality by providing history’s healthiest whole food nutrients to the modern world.
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.

A study of 39 obese adults placed on a ketogenic very low-calorie diet for 8 weeks found a mean loss of 13% of their starting weight and significant reductions in fat mass, insulin levels, blood pressure, and waist and hip circumferences. Their levels of ghrelin did not increase while they were in ketosis, which contributed to a decreased appetite. However during the 2-week period when they came off the diet, ghrelin levels and urges to eat significantly increased. [11]
Given that coconut oil is trendy, it’s been credited as a panacea for health ills — and given the general go-ahead to consume as much as you want. That’s not exactly the case. “There’s a controversy with coconut oil because of its high levels of saturated fats, which are the ones that clog arteries,” says Keene. But the argument some make is that coconut oil is different. Part of its fat is made up of medium-chain triglycerides, fatty acids that the body metabolizes quicker and are less likely to get stored by the body as fat, she says. That said, the USDA indicates that 1 tbsp has 121 calories, 13 g of fat (11 g are saturated fat), and 0 carbohydrates. Eat healthier unsaturated sources of fat first, and moderate amounts of these saturated sources, says Keene.
Low-carbohydrate diet advocates including Gary Taubes and David Ludwig have proposed a "carbohydrate-insulin hypothesis" in which carbohydrate is said to be uniquely fattening because it raises insulin levels and so causes fat to accumulate unduly.[8][28] The hypothesis appears to run counter to known human biology whereby there is no good evidence of any such association between the actions of insulin and fat accumulation and obesity.[6] The hypothesis predicted that low-carbohydrate dieting would offer a "metabolic advantage" of increased energy expenditure equivalent to 400-600 kcal/day, in accord with the promise of the Atkin's diet: a "high calorie way to stay thin forever".[8]

A cyclic ketogenic diet (or carb-cycling) is a low-carbohydrate diet with intermittent periods of high or moderate carbohydrate consumption. This is a form of the general ketogenic diet that is used as a way to maximize fat loss while maintaining the ability to perform high-intensity exercise. A ketogenic diet limits the number of grams of carbohydrate the dieter may eat, which may be anywhere between 0 and 50g per day. The remainder of the caloric intake must come primarily from fat sources and protein sources in order to maintain ketosis (the condition in which the body burns fats and uses ketones instead of glucose for fuel).
Sexual functioning in men was explored by means of the EMAS-Sexual Function Questionnaire (EMAS-SFQ) [27]. This questionnaire was completed in private and then placed in a sealed envelope by the participants without scrutiny by the researchers. The EMAS-SFQ has been found to exhibit excellent internal and test-retest reliability and convergent, divergent, and discriminant validity in psychometric analyses [27]. It consists of 16 items assessing sexual functioning, distress or worry relating to current functioning, and changes in sexual functioning compared with 1 year ago.

Instead of making your own cereal, you can always have a low-carb alternative. Try out chia seed pudding, flax granola sprinkled into coconut or almond milk, salted caramel pork rind cereal, or just mix together toasted nuts that are crushed and crispy. It’s quite easy to find a crunchy alternative to cereal (or just a low-carb replacement in general) so keep on the lookout and experiment for yourself to see which you like best.
There is a transition period in ketosis while the body is adapting to using fats and ketones instead of glucose as its main fuel. There can be negative symptoms during this period (fatigue, weakness, light-headedness, headaches, mild irritability), but they usually can be eased fairly easily. Most of these symptoms are over by the first week of a ketogenic diet, though some may extend to two weeks.
Some negative side effects of a long-term ketogenic diet have been suggested, including increased risk of kidney stones and osteoporosis, and increased blood levels of uric acid (a risk factor for gout). Possible nutrient deficiencies may arise if a variety of recommended foods on the ketogenic diet are not included. It is important to not solely focus on eating high-fat foods, but to include a daily variety of the allowed meats, fish, vegetables, fruits, nuts, and seeds to ensure adequate intakes of fiber, B vitamins, and minerals (iron, magnesium, zinc)—nutrients typically found in foods like whole grains that are restricted from the diet. Because whole food groups are excluded, assistance from a registered dietitian may be beneficial in creating a ketogenic diet that minimizes nutrient deficiencies.

“As an ophthalmologist, I use a low-carb, high-fat diet approach with intermittent fasting to treat and prevent vision loss associated with diabetic retinopathy in my patients. In addition to my ophthalmology practice, I also treat patients with obesity and metabolic diseases with positive results. I recommend the Diet Doctor website to all my patients so that they get a deep understanding of the low-carb, high-fat approach. It has all the valuable resources they need for a successful ketogenic lifestyle.”
Everyone responds to different levels of carbs, fat, and protein differently. It’s not enough to just eat what you think is a low amount of carbohydrates. Your metabolic history, daily activities, or any other factor may mean you can only tolerate 25 grams of carbs per day before getting kicked out of ketosis whereas someone else can tolerate up to 100 grams of carbs per day.
Hence, the 2 main objectives of this study were to assess the changes in body composition and muscle strength promoted by a VLCK diet in the treatment of obese patients and to compare different methodologies used to evaluate body composition. To achieve this, body composition was evaluated by 3 potent and well-validated techniques: dual-energy X-ray absorptiometry (DXA), multifrequency bioelectrical impedance analysis (MF-BIA), and air displacement plethysmography (ADP) at different stages during the weight reduction process induced by a VLCK diet.
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