Keto blogs and weight-loss websites recommend taking precautions—like making sure you’re staying hydrated, getting plenty of sleep, and finding ways to manage stress—to reduce the unpleasant effects of the ketogenic diet on your body. Some also recommend electrolytes, ketone supplements, or bone broth (which is high in sodium and other minerals) to replace some of what the body is missing in the early stage of the diet.

Well, we don’t really know why some people feel so bad after this dietary change. Is it related to a detox factor? Is it due to a carb withdrawal? Is there an immunologic reaction? Or is this a result of a change in the gut microbiome? Whatever the reason is, it appears the symptoms attributed to the keto flu may happen, not to everyone but to some people, after “cleaning up” their diet.
Although amino acids from protein foods can be converted to glucose, under experimental conditions, only a small percentage actually are. This may be related to individual factors, such as degree of insulin resistance. However, even people with type 2 diabetes usually do well with the adequate levels of protein Diet Doctor recommends, if their diets are also low carb.
Louise holds a Bachelors and Masters in Natural Sciences from Cambridge University (UK). She attended Columbia University for her JD and practiced law at Debevoise & Plimpton before co-founding Louise's Foods, Paleo Living Magazine, Nourishing Brands, & CoBionic. Louise has considerable research experience but enjoys creating products and articles that help move people just a little bit closer toward a healthy life they love. You can find her on Facebook or LinkedIn.
Insulin is a hormone that lets your body use or store sugar as fuel. Ketogenic diets make you burn through this fuel quickly, so you don’t need to store it. This means your body needs -- and makes -- less insulin. Those lower levels may help protect you against some kinds of cancer or even slow the growth of cancer cells. More research is needed on this, though.
A survey in 2005 of 88 paediatric neurologists in the US found that 36% regularly prescribed the diet after three or more drugs had failed, 24% occasionally prescribed the diet as a last resort, 24% had only prescribed the diet in a few rare cases, and 16% had never prescribed the diet. Several possible explanations exist for this gap between evidence and clinical practice.[34] One major factor may be the lack of adequately trained dietitians who are needed to administer a ketogenic diet programme.[31]
The ketogenic diet is a mainstream dietary therapy that was developed to reproduce the success and remove the limitations of the non-mainstream use of fasting to treat epilepsy.[Note 2] Although popular in the 1920s and '30s, it was largely abandoned in favour of new anticonvulsant drugs.[1] Most individuals with epilepsy can successfully control their seizures with medication. However, 20–30% fail to achieve such control despite trying a number of different drugs.[9] For this group, and for children in particular, the diet has once again found a role in epilepsy management.[1][10]
In 1921, Rollin Turner Woodyatt reviewed the research on diet and diabetes. He reported that three water-soluble compounds, β-hydroxybutyrate, acetoacetate, and acetone (known collectively as ketone bodies), were produced by the liver in otherwise healthy people when they were starved or if they consumed a very low-carbohydrate, high-fat diet.[10] Dr. Russell Morse Wilder, at the Mayo Clinic, built on this research and coined the term "ketogenic diet" to describe a diet that produced a high level of ketone bodies in the blood (ketonemia) through an excess of fat and lack of carbohydrate. Wilder hoped to obtain the benefits of fasting in a dietary therapy that could be maintained indefinitely. His trial on a few epilepsy patients in 1921 was the first use of the ketogenic diet as a treatment for epilepsy.[10]
The remaining calories in the keto diet come from protein — about 1 gram (g) per kilogram of body weight, so a 140-pound woman would need about 64 g of protein total. As for carbs: “Every body is different, but most people maintain ketosis with between 20 and 50 g of net carbs per day,” says Mattinson. Total carbohydrates minus fiber equals net carbs, she explains.
Natural fats and high-fat sauces: Using butter and cream for cooking can make your low-carb foods taste better and can make you feel more satisfied. Try a Béarnaise or Hollandaise sauce. If purchased pre-made, check the ingredients for starches and vegetable oils. Better yet, make it yourself. Coconut fat or olive oil are also good options. These are all healthy fats. Learn more
In general, a low-carb diet focuses on proteins, including meat, poultry, fish and eggs, and some nonstarchy vegetables. A low-carb diet generally excludes or limits most grains, legumes, fruits, breads, sweets, pastas and starchy vegetables, and sometimes nuts and seeds. Some low-carb diet plans allow small amounts of certain fruits, vegetables and whole grains.

Although many hypotheses have been put forward to explain how the ketogenic diet works, it remains a mystery. Disproven hypotheses include systemic acidosis (high levels of acid in the blood), electrolyte changes and hypoglycaemia (low blood glucose).[19] Although many biochemical changes are known to occur in the brain of a patient on the ketogenic diet, it is not known which of these has an anticonvulsant effect. The lack of understanding in this area is similar to the situation with many anticonvulsant drugs.[56]
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.
Now if you're thinking you'll just handle the problem by brushing and flossing a little more often, guess again. Since the breath odor is coming from metabolic changes and not necessarily a dental-related condition, traditional breath products are not likely to provide long-lasting relief. On the other hand drinking more water intake can do the trick.
Turns out, what’s low carbohydrate for one person isn’t for another. “There’s no medical definition of what low carb is,” says Columbus, Ohio–based Kelly Schmidt, RD. Basically, it’s reducing the number of carbs you eat from your norm. In general, however, a low-carb diet may include 50 to 100 grams (g) of carbohydrates per day, she says. Below that is considered a ketogenic diet, while 100 to 200 g of carbohydrates per day is a moderate-carb diet.
Because some cancer cells are inefficient in processing ketone bodies for energy, the ketogenic diet has also been suggested as a treatment for cancer.[59][60] A 2018 review looked at the evidence from preclinical and clinical studies of ketogenic diets in cancer therapy. The clinical studies in humans are typically very small, with some providing weak evidence for anti-tumour effect, particularly for glioblastoma, but in other cancers and studies, no anti-tumour effect was seen. Taken together, results from preclinical studies, albeit sometimes contradictory, tend to support an anti-tumor effect rather than a pro-tumor effect of the KD for most solid cancers.[61]
The Johns Hopkins Hospital protocol for initiating the ketogenic diet has been widely adopted.[43] It involves a consultation with the patient and their caregivers and, later, a short hospital admission.[19] Because of the risk of complications during ketogenic diet initiation, most centres begin the diet under close medical supervision in the hospital.[9]

Turns out, what’s low carbohydrate for one person isn’t for another. “There’s no medical definition of what low carb is,” says Columbus, Ohio–based Kelly Schmidt, RD. Basically, it’s reducing the number of carbs you eat from your norm. In general, however, a low-carb diet may include 50 to 100 grams (g) of carbohydrates per day, she says. Below that is considered a ketogenic diet, while 100 to 200 g of carbohydrates per day is a moderate-carb diet.
To get the most benefit from the keto diet, you should stay physically active. You might need to take it easier during the early ketosis period, especially if you feel fatigued or lightheaded. Walking, running, doing aerobics, weightlifting, training with kettlebells or whatever workout you prefer will boost your energy further. You can find books and online resources on how to adapt keto meals or snacks for athletic training.
The keto diet emphasizes weight loss through fat-burning. The goal is to quickly lose weight and ultimately feel fuller with fewer cravings, while boosting your mood, mental focus and energy. According to keto proponents, by slashing the carbs you consume and instead filling up on fats, you safely enter a state of ketosis. That’s when the body breaks down both dietary and stored body fat into substances called ketones. Your fat-burning system now relies mainly on fat – instead of sugar – for energy. While similar in some ways to familiar low-carb diets, the keto diet’s extreme carb restrictions – about 20 net carbs a day or less, depending on the version – and the deliberate shift into ketosis are what set this increasingly popular diet apart. In fact, other eating plans are pulling in keto elements, so you can find versions like eco-keto and at least one commercial diet that incorporates keto-friendly products.
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