Low-carb diets may help prevent or improve serious health conditions, such as metabolic syndrome, diabetes, high blood pressure and cardiovascular disease. In fact, almost any diet that helps you shed excess weight can reduce or even reverse risk factors for cardiovascular disease and diabetes. Most weight-loss diets — not just low-carb diets — may improve blood cholesterol or blood sugar levels, at least temporarily.

Stock up: The Amazon Fresh grocery delivery service makes it easy to ensure you always have keto-friendly veggies in the fridge. We love its delivery scheduling tool; simply fill your cart, then decide which day and timeframe you'd like your groceries delivered. One of our faves: Pre-Cut Zucchini Noodles are great for whipping up low-carb "pasta" dishes.
Long-term use of the ketogenic diet in children increases the risk of slowed or stunted growth, bone fractures, and kidney stones.[18] The diet reduces levels of insulin-like growth factor 1, which is important for childhood growth. Like many anticonvulsant drugs, the ketogenic diet has an adverse effect on bone health. Many factors may be involved such as acidosis and suppressed growth hormone.[38] About one in 20 children on the ketogenic diet develop kidney stones (compared with one in several thousand for the general population). A class of anticonvulsants known as carbonic anhydrase inhibitors (topiramate, zonisamide) are known to increase the risk of kidney stones, but the combination of these anticonvulsants and the ketogenic diet does not appear to elevate the risk above that of the diet alone.[39] The stones are treatable and do not justify discontinuation of the diet.[39] Johns Hopkins Hospital now gives oral potassium citrate supplements to all ketogenic diet patients, resulting in one-seventh of the incidence of kidney stones.[40] However, this empiric usage has not been tested in a prospective controlled trial.[9] Kidney stone formation (nephrolithiasis) is associated with the diet for four reasons:[39]

And if you can't survive without your pasta, there are plenty of products out there like Explore Cuisine's organic black bean spaghetti that give you the pasta experience without the carbs. There are also tons of keto-friendly restaurants—like Red Lobster, Olive Garden, and Texas Roadhouse—that can allow you to treat yourself to a night out without coming out of ketosis.
The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet that in medicine is used primarily to treat difficult-to-control (refractory) epilepsy in children. The diet forces the body to burn fats rather than carbohydrates. Normally, the carbohydrates contained in food are converted into glucose, which is then transported around the body and is particularly important in fueling brain function. However, if little carbohydrate remains in the diet, the liver converts fat into fatty acids and ketone bodies. The ketone bodies pass into the brain and replace glucose as an energy source. An elevated level of ketone bodies in the blood, a state known as ketosis, leads to a reduction in the frequency of epileptic seizures.[1] Around half of children and young people with epilepsy who have tried some form of this diet saw the number of seizures drop by at least half, and the effect persists even after discontinuing the diet.[2] Some evidence indicates that adults with epilepsy may benefit from the diet, and that a less strict regimen, such as a modified Atkins diet, is similarly effective.[1] Potential side effects may include constipation, high cholesterol, growth slowing, acidosis, and kidney stones.[3]
Variations on the Johns Hopkins protocol are common. The initiation can be performed using outpatient clinics rather than requiring a stay in hospital. Often, no initial fast is used (fasting increases the risk of acidosis, hypoglycaemia, and weight loss). Rather than increasing meal sizes over the three-day initiation, some institutions maintain meal size, but alter the ketogenic ratio from 2:1 to 4:1.[9]
For patients who benefit, half achieve a seizure reduction within five days (if the diet starts with an initial fast of one to two days), three-quarters achieve a reduction within two weeks, and 90% achieve a reduction within 23 days. If the diet does not begin with a fast, the time for half of the patients to achieve an improvement is longer (two weeks), but the long-term seizure reduction rates are unaffected.[44] Parents are encouraged to persist with the diet for at least three months before any final consideration is made regarding efficacy.[9]
Implementing the diet can present difficulties for caregivers and the patient due to the time commitment involved in measuring and planning meals. Since any unplanned eating can potentially break the nutritional balance required, some people find the discipline needed to maintain the diet challenging and unpleasant. Some people terminate the diet or switch to a less demanding diet, like the modified Atkins diet or the low-glycaemic index treatment diet, because they find the difficulties too great.[42]
The best starting point for a transition phase is to eliminate all processed carbs and grains, and focus on getting your carbs only from starchy fruit and vegetables. You can slowly phase out carbs each day by reducing the amount you’re eating at each meal until eventually, carbs will only be 5% of your daily diet, which is when your body can enter ketosis.
Note: Because you'll be excluding some major food groups on the keto diet (grains, many fruits) you should definitely think about taking a multivitamin—especially one that contains folic acid, which helps your body make new cells and is often found in enriched breads, cereals, and other grain products, says Julie Upton, R.D., cofounder of nutrition website Appetite for Health.
Cynthia Sass, MPH, RD, Health’s contributing nutrition editor, says that many of her clients who have tried the ketogenic diet have also reported irritability and changes in mood. And while people don’t necessarily feel hungry on the keto diet—thanks to its high allowance for fat and moderate amounts of protein—some do report serious sugar cravings.
There are many ways in which epilepsy occurs. Examples of pathological physiology include: unusual excitatory connections within the neuronal network of the brain; abnormal neuron structure leading to altered current flow; decreased inhibitory neurotransmitter synthesis; ineffective receptors for inhibitory neurotransmitters; insufficient breakdown of excitatory neurotransmitters leading to excess; immature synapse development; and impaired function of ionic channels.[7]
Not everyone should opt for a low-carb diet. If you’re pregnant, it’s possible to be on a lower-carb diet (and may even be indicated if you are told you have gestational diabetes), but talk to your doctor to find out what’s right for you and to ensure that you’re covering any potential nutrient gaps. “Many women who are pregnant find that the thought of eating protein and fat makes them sick,” says Spritzler. This can be especially common in the first trimester. “They naturally want more carbs. You should always listen to your body,” she says.
Has adding more water, salt and fat not helped very much? Are you still feeling achy, tired and off? We recommend you try to endure it for a few more days until the symptoms pass. Research has shown that a very-low-carb diet is best for weight loss and metabolic issues like type 2 diabetes.Keto flu symptoms are only temporary – they’ll be long gone when you are a fat burner.
Low-carb diets, especially very low-carb diets, may lead to greater short-term weight loss than do low-fat diets. But most studies have found that at 12 or 24 months, the benefits of a low-carb diet are not very large. A 2015 review found that higher protein, low-carbohydrate diets may offer a slight advantage in terms of weight loss and loss of fat mass compared with a normal protein diet.
Lots of apps and websites offer keto diet challenges—basically, a blueprint for the keto diet with a fixed starting and ending point (they typically last for a week to a month, though some may be longer). Speaking of apps, plenty of keto-centric ones are right at your fingertips (a.k.a., your smartphone), like the KetoDiet app, which can help you calculate your macros and track your keto diet effectively.

If you want to slam a protein shake post-workout, that's probably fine as long as you've got room for it in your macros. But shoot for one that is very low—like, zero—in carbohydrates. Pure isolates, such as Signature 100% Whey Isolate, are extremely low in carbohydrate. If you struggle to fit fat in during the day, toss a tablespoon of olive oil in with your shake. You won't taste it, and it gives a quick 13-14 grams of fat.


Ketosis is pretty different from what your body is used to, and this onslaught of symptoms is its way of dealing with carb withdrawal—and adapting, explains Kristen Mancinelli, RD, author of The Ketogenic Diet. “It takes a while, usually a week or two, for the metabolic machinery to shift to fat-burning mode. And you’ll feel pretty crummy while the transition is happening,” she says.
It usually takes three to four days for your body to go into ketosis because you have to use up your body's stores of glucose, i.e., sugar first, Keatley says. Any major diet change can give you some, uh, issues, and Keatley says he often sees patients who complain of IBS-like symptoms and feeling wiped out at the beginning of the diet. (The tiredness happens because you have less access to carbs, which give you quick energy, he explains.)
Note: Because you'll be excluding some major food groups on the keto diet (grains, many fruits) you should definitely think about taking a multivitamin—especially one that contains folic acid, which helps your body make new cells and is often found in enriched breads, cereals, and other grain products, says Julie Upton, R.D., cofounder of nutrition website Appetite for Health.
Low-carb diets may help prevent or improve serious health conditions, such as metabolic syndrome, diabetes, high blood pressure and cardiovascular disease. In fact, almost any diet that helps you shed excess weight can reduce or even reverse risk factors for cardiovascular disease and diabetes. Most weight-loss diets — not just low-carb diets — may improve blood cholesterol or blood sugar levels, at least temporarily.
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]
That’s not to say everyone starting out on a keto diet ends up wholly incapacitated for days. “You might find that you fatigue more quickly or that exercise seems harder than normal,” says Seattle-based nutritionist and Academy of Nutrition and Dietetics spokesperson Ginger Hultin, MS, RDN. Your body might also have an easier time transitioning (read: fewer symptoms) if you were already eating a relatively low-carb diet, Mancinelli explains.

Hypoglycemia: Though the diet can lower A1c levels, that may mean you’re at a higher risk of blood sugar that dips too low, especially if you’re also taking medicine for your diabetes. Let your doctor or diabetes educator know if you try the keto diet. They can advise you about checking your blood sugar, taking your medicines, and what to do when your blood sugar drops too low.
Eating slightly more carbs may potentially slow down weight loss and mute rapid, dramatic health improvements, but it can still lead to better health, especially if you are cutting out sugar and processed foods. And keto flu will no longer be an issue. Once you’ve adapted to low-carb eating, feel free to try eating less than 20 grams of carbs again to see whether your body prefers this or slightly higher carb intake.
Have an electronics curfew: According to Harvard University, the blue light from tablets, laptops, and smartphones can seriously interfere with your circadian rhythm, and make it difficult for you to fall asleep (6). Having an electronics curfew (ideally at least two hours before you go to bed) is an excellent way to improve your sleep quality. Why not replace the nightly Instagram, Facebook, and email-checking time with a bedtime ritual that helps you relax and unwind?
Those issues can be part of what's known as the “keto flu,” Warren says. Other side effects of the keto diet, all of which are tied to carb withdrawal, can include lightheadedness, nausea, mental fog, cramps, and headaches, in addition to tiredness. Luckily, the keto flu doesn't usually last more than a week—which is coincidentally about when people start to see the number on the scale go down, says Warren.
In 1994, Hollywood producer Jim Abrahams, whose son's severe epilepsy was effectively controlled by the diet, created the Charlie Foundation for Ketogenic Therapies to further promote diet therapy. Publicity included an appearance on NBC's Dateline program and ...First Do No Harm (1997), a made-for-television film starring Meryl Streep. The foundation sponsored a research study, the results of which—announced in 1996—marked the beginning of renewed scientific interest in the diet.[1]
Short-term results for the LGIT indicate that at one month approximately half of the patients experience a greater than 50% reduction in seizure frequency, with overall figures approaching that of the ketogenic diet. The data (coming from one centre's experience with 76 children up to the year 2009) also indicate fewer side effects than the ketogenic diet and that it is better tolerated, with more palatable meals.[18][50]
"Plenty of people jump right in, thinking all they have to do is cut carbs and increase fat. All of a sudden, they hit a wall and get 'keto flu.' They feel tired, lethargic, and experience headaches," Wittrock says. "The primary reason they get these symptoms is lack of the three primary electrolytes: sodium, potassium, and magnesium. If you're deficient in any of these, you'll suffer mentally and physically. This is the single biggest reason people fail on the keto diet."
You've likely heard horror stories of what competitors feel like when they cut carbs low, or when the average bro talks about going keto. However, the odds are that those people were not actually in nutritional ketosis, or more importantly, following a well-formulated ketogenic diet. Yes, you may experience some fogginess and discomfort, but it doesn't have to be intense if you handle it right.
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.
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