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. One major factor may be the lack of adequately trained dietitians who are needed to administer a ketogenic diet programme.
But beyond that, experts aren't convinced that the keto diet has any other scientifically proven health benefits. In fact, it may have some distinct downsides. If you follow the keto diet incorrectly, for example (like by eating lots of saturated fats, versus healthy unsaturated fats), you're at risk of raising your cholesterol levels. “The best strategy to keep your heart healthy is to get as much fat as possible from unsaturated sources such as olive, avocado and canola oils, nuts, seeds, avocados, and olives," says Ansel. For some people, it's possible to actually improve cholesterol if the fats in their diet are from varied and healthy sources, says Harvey.
Just because you're not eating all your fave carb-y foods, that doesn't mean you're going to go hungry. You'll be loading up on healthy fats (like olive oil and avocado), along with plenty of lean protein like grass-fed beef and chicken, and leafy greens or other non-starchy veggies. (Check out this printable keto diet grocery list, plus this additional comprehensive list of keto foods recommended by nutritionists, to get started.)
The ketogenic diet reduces seizure frequency by more than 50% in half of the patients who try it and by more than 90% in a third of patients. Three-quarters of children who respond do so within two weeks, though experts recommend a trial of at least three months before assuming it has been ineffective. Children with refractory epilepsy are more likely to benefit from the ketogenic diet than from trying another anticonvulsant drug. Some evidence indicates that adolescents and adults may also benefit from the diet.
Fairly recently, the diet was introduced as a weight-loss diet by an Italian professor of surgery, Dr. Gianfranco Cappello of Sapienza University in Rome. In his 2012 study, about 19,000 dieters received a high-fat liquid diet via a feeding tube inserted down the nose. The study showed an average weight loss of more than 20 pounds in participants, most of whom kept it off for at least a year. The researchers reported a few minor side effects, like fatigue.
Severely restricting carbohydrates to less than 0.7 ounces (20 grams) a day can result in a process called ketosis. Ketosis occurs when you don't have enough sugar (glucose) for energy, so your body breaks down stored fat, causing ketones to build up in your body. Side effects from ketosis can include nausea, headache, mental and physical fatigue, and bad breath.
Yes, ramping up your fat consumption can help speed up the transition of burning fat for fuel instead of glucose. Have a tablespoon of coconut oil in your coffee or tea, snack on half of an avocado and some bacon, and load up on egg yolks at dinner before you reach for the carbs, and remember: the keto flu too shall pass (and the benefits that follow ketosis will be totally worth it in the end).
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.
The nerve impulse is characterised by a great influx of sodium ions through channels in the neuron's cell membrane followed by an efflux of potassium ions through other channels. The neuron is unable to fire again for a short time (known as the refractory period), which is mediated by another potassium channel. The flow through these ion channels is governed by a "gate" which is opened by either a voltage change or a chemical messenger known as a ligand (such as a neurotransmitter). These channels are another target for anticonvulsant drugs.
Low-carb diets may improve high-density lipoprotein (HDL) cholesterol and triglyceride values slightly more than do moderate-carb diets. That may be due not only to how many carbs you eat but also to the quality of your other food choices. Lean protein (fish, poultry, legumes), healthy fats (monounsaturated and polyunsaturated) and unprocessed carbs — such as whole grains, legumes, vegetables, fruits and low-fat dairy products — are generally healthier choices.
Yes, they're technically a fruit, but we think olives deserve a shout-out all of their own, since they're also a great source of healthy fats and are one of a few keto-approved packaged foods. Plus, they're a great source of antioxidants, will satisfy your craving for something salty, and are blissfully low-carb. “About a palm's worth only has 3 grams of net carbs,” Sarah Jadin, RD, told Health in a previous interview.
"I recommend only 5 percent of calories coming from carbs, which usually averages out to less than 30 grams," he says. "I understand why people get nervous and panic, thinking 'Can I even eat a salad?' This is why I recommend tracking only 'net carbs', which are total carbs minus fiber. For example, an avocado has 12 grams of carbs but 10 grams of fiber, which means it has 2 grams of net carbs. Also, green leafy vegetables are very nutritious and contain a lot of fiber, so you can almost eat them as much as you want and stay below your limit.
Fruit: While berries like blueberries, raspberries and strawberries are fine in small to moderate amounts, be careful with other fruit. They are fairly high in carbs and sugar, which can raise blood sugar, may slow down weight loss and can possibly worsen metabolic issues. Consider it nature’s candy: fine for a special treat, but probably not something to consume daily on a low-carb diet. Learn more
In terms of weight loss, you may be interested in trying the ketogenic diet because you’ve heard that it can make a big impact right away. And that’s true. “Ketogenic diets will cause you to lose weight within the first week,” says Mattinson. She explains that your body will first use up all of its glycogen stores (the storage form of carbohydrate). With depleted glycogen, you’ll drop water weight. While it can be motivating to see the number on the scale go down (often dramatically), do keep in mind that most of this is water loss initially.
In its 2016 report “Healthy Eating Guidelines & Weight Loss Advice,” the Public Health Collaboration, a U.K. nonprofit, evaluated evidence on low-carbohydrate, high-fat diets. (The keto diet falls under the LCHF umbrella.) Among 53 randomized clinical trials comparing LCHF diets to calorie-counting, low-fat diets, a majority of studies showed greater weight loss for the keto-type diets, along with more beneficial health outcomes. The collaboration recommends weight-loss guidelines that include a low-carbohydrate, high-fat diet of real (rather than processed) foods as an acceptable, effective and safe approach.
The ketone bodies are possibly anticonvulsant; in animal models, acetoacetate and acetone protect against seizures. The ketogenic diet results in adaptive changes to brain energy metabolism that increase the energy reserves; ketone bodies are a more efficient fuel than glucose, and the number of mitochondria is increased. This may help the neurons to remain stable in the face of increased energy demand during a seizure, and may confer a neuroprotective effect.
If you’ve recently switched to the keto diet and you’re feeling drowsy, achy, nauseous, dizzy, and irritable, don’t worry. These symptoms are your body’s natural reaction to removing carbs from your diet, and while it may have you second guessing your keto diet decision, we promise you these keto flu symptoms will pass. Stick with it, and soon you’ll be reaping the energizing, fat-burning rewards that come with ketosis.
No matter what your diet has been before now, keto will be a big change. If you're coming from a standard American diet (SAD), your carbs will go way down, your protein may either go up or down, and your fat will go way up. If you're coming from a bodybuilding-style diet, your fat intake will jump to alarming levels, and your protein will likely drop significantly.
What can you drink on a ketogenic diet? Water is the perfect drink, and coffee or tea are fine too. Ideally, use no sweeteners, especially sugar. A splash of milk or cream in your coffee or tea is OK, but beware that the carbs can add up if you drink multiple cups in a day (and definitely avoid caffe lattes!). The occasional glass of wine is fine too.