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.)
On a ketogenic diet, you’re generally eating a diet that’s high in fat (roughly 70 percent of your total calories come from fat), moderate in protein (about 20 percent of your calories), and low in carbohydrate (about 5 percent of calories). By limiting carbohydrates (to usually less than 45 grams for the average person), your body lacks the glucose (from carbs) that it normally uses for energy, so it eventually switches over to burning fat as its primary fuel source instead; through a metabolic process called ketosis, the liver converts the fat into fragments of fatty acids called ketones, which power the brain and other organs and tissues.
When it comes to starting the keto diet (or any diet for that matter), there's one thing all experts agree on. You *must* have a plan. "Never try to wing a keto diet," says Julie Stefanski, R.D.N., C.S.S.D., L.D.N., a dietitian based in York, PA, who specializes in the ketogenic diet. "Set a start date and get prepared by reorganizing your pantry, planning out meal and snack options, and purchasing appropriate foods and dietary supplements," she says. "The biggest reason people have a hard time sticking with keto is that people don't have enough interesting foods to turn to, and high-carb favorites win out over good intention. If you didn't buy foods at the grocery store that fit the guidelines, there won't be an easy option in the fridge when you really need it." (A great place to start is this List of High-Fat Keto Foods Anyone Can Add to Their Diet.)

But people who started following the keto diet noticed weight loss for a few reasons: When you eat carbs, your body retains fluid in order to store carbs for energy (you know, in case it needs it). But when you’re not having much in the carb department, you lose this water weight, says Warren. Also, it's easy to go overboard on carbohydrates—but if you're loading up on fat, it may help curb cravings since it keeps you satisfied.
You can have a completely smooth transition into ketosis, or…not. While your body is adapting to using ketones as your new fuel source, you may experience a range of uncomfortable short-term symptoms. These symptoms are referred to as “the keto flu.” Low-sodium levels are often to blame for symptoms keto flu, since the kidneys secrete more sodium when you’re in ketosis, says Volek. A few side effects:
"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."
Electrolytes: To reiterate, maintaining electrolyte balances is critical on a ketogenic diet, in order to prevent side effects and the “keto-flu.” While this can be done exclusively through whole foods, some individuals may require additional sources. Sodium, magnesium, potassium, and in some cases, calcium, can all be replenished via supplementation.
Keto for Alzheimer’s Disease: One characteristic of Alzheimer’s disease is insulin resistance in the brain (hence why it’s now being referred to as type III diabetes), which robs this critical tissue of energy. Limiting glucose while introducing ketones may be an effective mechanism for replenishing the energy in the tissue. The higher level of ketone production accompanied with a ketogenic diet is another example as to why this diet is superior to one that simply restricts carbohydrate intake. Additionally, Alzheimer’s disease is characterized by beta-amyloid deposition, which may also be mitigated by the implementation of a ketogenic diet.

Refreshing, just plain refreshing. Maybe it’s because I’m a nurse anesthetist and I’m more comfortable reading research or journal articles than opinions, but this is an excellent article! It addresses all the questions ,concerns and misnomer surrounding the KD. It is well written, easy to read and gave me that additional depth of understanding that I was desiring. Thank you, thank you, thank you!
Among the many biological modifications that must occur for sufficient ketone body utilization, the upregulation of ketone transporters must take place. Thus, research has demonstrated that chronic elevations in blood ketone levels positively increase the number of these transporters. Therefore adherence, especially during the initial stages of the keto diet for beginners, is critical.
A short-lived increase in seizure frequency may occur during illness or if ketone levels fluctuate. The diet may be modified if seizure frequency remains high, or the child is losing weight.[19] Loss of seizure-control may come from unexpected sources. Even "sugar-free" food can contain carbohydrates such as maltodextrin, sorbitol, starch, and fructose. The sorbitol content of suntan lotion and other skincare products may be high enough for some to be absorbed through the skin and thus negate ketosis.[31]
Quite simply, for the majority of people the answer is a resounding “yes!” Due to its high-fat nature, it is often perceived as a health risk, often deterring individuals from trying it. Despite this misconception, research has demonstrated that the ketogenic diet is safe for most people, providing you don’t have one of the following conditions (even if you have any of these conditions, the ketogenic diet may still be safe, but you would need to work very closely with your doctor):
Blood Ketone Meter: Measuring ketone levels in the blood more accurately measures and indicates an individual’s metabolic state of ketosis. Similar to measuring blood glucose levels, this method also uses a blood meter and a chemo-sensitive strip made specifically to measure ketones in the blood called beta‑hydroxybutyrate (βHB). As with blood glucose measurements, a blood sample can be acquired from a finger prick. The ketone level displays on the meter within a few seconds of a sample placement on the strip.
“You are literally starving” on an intermittent fasting diet, Keatley says. “Methods such as this are attractive as weight loss can go from one pound a week to four pounds, but this is mostly lean muscle which is essential to healthy functioning as you age and is very hard to get back once it is gone,” he adds. So…it’s not really recommended that you try this unless you hash it out with your doctor or nutritionist to make sure it's a fit for you and your lifestyle.
When in the hospital, glucose levels are checked several times daily and the patient is monitored for signs of symptomatic ketosis (which can be treated with a small quantity of orange juice). Lack of energy and lethargy are common, but disappear within two weeks.[17] The parents attend classes over the first three full days, which cover nutrition, managing the diet, preparing meals, avoiding sugar, and handling illness.[19] The level of parental education and commitment required is higher than with medication.[44]

Endurance Performance: Traditionally, endurance athletes tend to consume a high amount of carbohydrates in order to “fill up” their fuel stores (i.e. glycogen) for competitions. Thus, a diet where carbohydrates are restricted seems counter-intuitive for these individuals. However, Dr. Jeff Volek’s research showed that once an individual is keto-adapted, not only is their performance the same or better than those consuming high levels of carbohydrates, but their glycogen “fuel stores” are the same as well.[11] Despite consuming a diet lower in carbohydrates, these athletes are able to adapt and utilize a nearly limitless supply of fat as their primary fuel source.
One thing many people love about keto diet plans is that tracking your food is optional. "One of the biggest benefits of the ketogenic diet is that there's no need to meticulously track your calories as you may in other diets," notes Dr. Josh Axe, D.N.M., C.N.S., D.C., founder of DrAxe.com, best-selling author of Eat Dirt, and cofounder of Ancient Nutrition. "Because you're filling up on fat and protein, you're more likely to feel satisfied and energized all day long, which causes you to naturally eat less." This isn't to say that food tracking on a keto meal plan is discouraged. "Some people may find calorie counting a useful tool to be more mindful and aware of what they're eating, but it's not necessary on the ketogenic diet," says Dr. Axe, but there's no need to get too stressed about hitting a certain caloric goal, especially if you're not trying to lose weight. (Related: The #1 Reason to Stop Counting Calories)
During the 1920s and 1930s, when the only anticonvulsant drugs were the sedative bromides (discovered 1857) and phenobarbital (1912), the ketogenic diet was widely used and studied. This changed in 1938 when H. Houston Merritt, Jr. and Tracy Putnam discovered phenytoin (Dilantin), and the focus of research shifted to discovering new drugs. With the introduction of sodium valproate in the 1970s, drugs were available to neurologists that were effective across a broad range of epileptic syndromes and seizure types. The use of the ketogenic diet, by this time restricted to difficult cases such as Lennox–Gastaut syndrome, declined further.[10]
You’ve probably heard about the low carb, high fat diet that’s so popular among actors and models, and with good reason: low carb diets offer proper nourishment with whole foods, while keeping your body burning fat for fuel. This is a great way to be, as it makes fat loss largely effortless! But where does this “ketogenic” word fit into the picture?
On a ketogenic diet, your entire body switches its fuel supply to run mostly on fat, burning fat 24-7. When insulin levels become very low, fat burning can increase dramatically. It becomes easier to access your fat stores to burn them off. This is great if you’re trying to lose weight, but there can also be other, less obvious benefits, such as less hunger and a steady supply of energy (without the sugar peaks and valleys we can get from high carb meals). This may help keep you alert and focused.

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.
Because the ketogenic diet alters the body's metabolism, it is a first-line therapy in children with certain congenital metabolic diseases such as pyruvate dehydrogenase (E1) deficiency and glucose transporter 1 deficiency syndrome,[35] which prevent the body from using carbohydrates as fuel, leading to a dependency on ketone bodies. The ketogenic diet is beneficial in treating the seizures and some other symptoms in these diseases and is an absolute indication.[36] However, it is absolutely contraindicated in the treatment of other diseases such as pyruvate carboxylase deficiency, porphyria, and other rare genetic disorders of fat metabolism.[9] Persons with a disorder of fatty acid oxidation are unable to metabolise fatty acids, which replace carbohydrates as the major energy source on the diet. On the ketogenic diet, their bodies would consume their own protein stores for fuel, leading to ketoacidosis, and eventually coma and death.[37]
The meal plan is designed to ensure you get three balanced, healthy meals a day that address fiber, satiation, and adequate protein intake. The greatest part of a ketogenic diet is the fact that it spares muscle loss, where a carb-based diet doesn’t. Weight lost in a high carb, calorie-restricted diet will often come both from muscle and fat, whereas with keto, you can burn fat without sacrificing muscle. This is referred to often as “body recomposition” and leaves you with a much more preferred physique after weight loss.
Now that ketogenic diets have become popular, many keto hybrid diets have sprung up, including plant-based versions. (One is “ketotarian,” which is predominantly plant-based but includes the option of eggs, ghee, and fish and shellfish.) While this approach can be healthy, Hultin cautions against trying keto as a vegan. “Because you can’t eat beans or lentils on a ketogenic diet, and nuts and seeds are even limited due to their carbohydrate content, you’re really just left with some tofu and will need to rely on low-carb protein powder,” she says. There is a good possibility this won’t pan out. “I don’t see this as a sustainable diet due to the extreme restrictions,” she says.
Keto for Parkinson’s Disease: Parkinson’s disease develops as a result of neuron death in the midbrain and is typically accompanied by tremors, as well as physical and cognitive impairments. Due to its neuroprotective effects, the ketogenic diet may help protect neurons, increase energy production and mitochondrial function, lower inflammation, and improve motor function—all of which play a role in Parkinson’s disease.
Hi 😀 yes I have a question, just starting this Keto diet, so we’re very new at this but my boyfriend had a heart attack 8 years ago so we need to be very careful to not get to high on fat with him. Can he still benefit from this diet. His Doctor said he needs to get some of his weight off he is having a hard time breathing. The Doctor said a low carb diet. But I, we would like to try the Keto diet.
A simple standby, but one that ketoers adore. 2 or 3 fried eggs and some bacon might not sound like much, but it’s full of protein that will keep you full and energized all morning. Take the opportunity on the weekend to lay your bacon strips on a single cookie sheet and bake in the oven for 20 minutes at 400 degrees. The result is the best bacon you’ve ever had, in a big batch, with no sitting over a popping, hissing frying pan.
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