The ketogenic diet is a low carb, high fat diet that puts the body into a metabolic state called ketosis. When this happens, the body burns fat for energy and produces ketones to supply energy for the brain. Studies show this type of diet can help with weight loss and improving health conditions like diabetes, cancer, epilepsy, and Alzheimer's disease. A ketogenic diet typically contains 70% fat, 20% protein, and only 10% carbs. This summary outlines the basics of what a ketogenic diet is and some of its potential health benefits.

1. NUTRITION
The Ketogenic Diet: A Detailed
Beginner’s Guide to Keto
Written by Rudy Mawer, MSc, CISSN — Medically reviewed by Amy Richter,
RD, Nutrition — Updated on October 22, 2020
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The ketogenic diet (or keto diet, for short) is a low carb, high fat diet that
offers many health benefits.
In fact, many studies show that this type of diet can help you lose weight
and improve your health (1).
Ketogenic diets may even have benefits against diabetes, cancer,
epilepsy, and Alzheimer’s disease (2, 3, 4, 5).
Here is a detailed beginner’s guide to the keto diet.
u Evidence Based
What It Is Diet types Ketosis Weight loss Diabetes
Other benefits Foods to avoid Foods to eat Sample plan Snacks
Tips Dining out Side effects Risks Supplements FAQs
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2. Keto basics
The ketogenic diet is a very low carb, high fat diet that shares many
similarities with the Atkins and low carb diets.
It involves drastically reducing carbohydrate intake and replacing it with
fat. This reduction in carbs puts your body into a metabolic state called
ketosis.
When this happens, your body becomes incredibly efficient at burning fat
for energy. It also turns fat into ketones in the liver, which can supply
energy for the brain (6).
Ketogenic diets can cause significant reductions in blood sugar and
insulin levels. This, along with the increased ketones, has some health
benefits (6, 7, 8).
SUMMARY
The keto diet is a low carb, high fat diet. It lowers blood sugar
and insulin levels and shifts the body’s metabolism away from
carbs and toward fat and ketones.
What is a ketogenic diet?

3. There are several versions of the ketogenic diet, including:
Standard ketogenic diet (SKD): This is a very low carb, moderate
protein and high fat diet. It typically contains 70% fat, 20% protein,
and only 10% carbs (9).
Cyclical ketogenic diet (CKD): This diet involves periods of higher
carb refeeds, such as 5 ketogenic days followed by 2 high carb
days.
Targeted ketogenic diet (TKD): This diet allows you to add carbs
around workouts.
High protein ketogenic diet: This is similar to a standard ketogenic
diet, but includes more protein. The ratio is often 60% fat, 35%
protein, and 5% carbs.
However, only the standard and high protein ketogenic diets have been
studied extensively. Cyclical or targeted ketogenic diets are more
advanced methods and primarily used by bodybuilders or athletes.
The information in this article mostly applies to the standard ketogenic
diet (SKD), although many of the same principles also apply to the other
versions.
SUMMARY
There are several versions of the keto diet. The standard (SKD)
version is the most researched and most recommended.
Different types of ketogenic diets
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4. Ketosis is a metabolic state in which your body uses fat for fuel instead of
carbs.
It occurs when you significantly reduce your consumption of
carbohydrates, limiting your body’s supply of glucose (sugar), which is the
main source of energy for the cells.
Following a ketogenic diet is the most effective way to enter ketosis.
Generally, this involves limiting carb consumption to around 20 to 50
grams per day and filling up on fats, such as meat, fish, eggs, nuts, and
healthy oils (6).
It’s also important to moderate your protein consumption. This is because
protein can be converted into glucose if consumed in high amounts,
which may slow your transition into ketosis (10).
Practicing intermittent fasting could also help you enter ketosis faster.
There are many different forms of intermittent fasting, but the most
common method involves limiting food intake to around 8 hours per day
and fasting for the remaining 16 hours (11).
Blood, urine, and breath tests are available, which can help determine
whether you’ve entered ketosis by measuring the amount of ketones
produced by your body.
Certain symptoms may also indicate that you’ve entered ketosis, including
increased thirst, dry mouth, frequent urination, and decreased hunger or
appetite (12).
SUMMARY
Ketosis is a metabolic state in which your body uses fat for fuel
What is ketosis?

5. instead of carbs. Modifying your diet and practicing intermittent
fasting can help you enter ketosis faster. Certain tests and
symptoms can also help determine whether you’ve entered
ketosis.
A ketogenic diet is an effective way to lose weight and lower risk factors
for disease (1, 2, 3, 4, 5).
In fact, research shows that the ketogenic diet may be as effective for
weight loss as a low fat diet (13, 14, 15).
What’s more, the diet is so filling that you can lose weight without
counting calories or tracking your food intake (16).
One review of 13 studies found that following a very low carb, ketogenic
diet was slightly more effective for long-term weight loss than a low fat
diet. People who followed the keto diet lost an average of 2 pounds (0.9
kg) more than the group that followed a low fat diet (13).
What’s more, it also led to reductions in diastolic blood pressure and
triglyceride levels (13).
Another study in 34 older adults found that those who followed a
ketogenic diet for 8 weeks lost nearly five times as much total body fat as
those who followed a low fat diet (17).
The increased ketones, lower blood sugar levels, and improved insulin
sensitivity may also play a key role (18, 19).
For more details on the weight loss effects of a ketogenic diet, read this
article.
SUMMARY
A ketogenic diet can help you lose slightly more weight than a
low fat diet. This often happens with less hunger.
Ketogenic diets can help you lose weight

6. Diabetes is characterized by changes in metabolism, high blood sugar,
and impaired insulin function (20).
The ketogenic diet can help you lose excess fat, which is closely linked to
type 2 diabetes, prediabetes, and metabolic syndrome (21, 22, 23, 24).
One older study found that the ketogenic diet improved insulin sensitivity
by a whopping 75% (25).
A small study in women with type 2 diabetes also found that following a
ketogenic diet for 90 days significantly reduced levels of hemoglobin A1C,
which is a measure of long-term blood sugar management (26).
Another study in 349 people with type 2 diabetes found that those who
followed a ketogenic diet lost an average of 26.2 pounds (11.9 kg) over a
2-year period. This is an important benefit when considering the link
between weight and type 2 diabetes (24, 27).
What’s more, they also experienced improved blood sugar management,
and the use of certain blood sugar medications decreased among
participants throughout the course of the study (27).
For more information, check out this article on the benefits of low carb
diets for people with diabetes.
SUMMARY
The ketogenic diet can boost insulin sensitivity and cause fat
loss, leading to significant health benefits for people with type 2
diabetes or prediabetes.
Ketogenic diets for diabetes and prediabetes
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7. The ketogenic diet actually originated as a tool for treating neurological
diseases such as epilepsy.
Studies have now shown that the diet can have benefits for a wide variety
of different health conditions:
Heart disease. The ketogenic diet can help improve risk factors like
body fat, HDL (good) cholesterol levels, blood pressure, and blood
sugar (28, 29).
Cancer. The diet is currently being explored as an additional
treatment for cancer, because it may help slow tumor growth. (4, 30,
31).
Alzheimer’s disease. The keto diet may help reduce symptoms of
Alzheimer’s disease and slow its progression (5, 32, 33).
Epilepsy. Research has shown that the ketogenic diet can cause
significant reductions in seizures in epileptic children (3).
Parkinson’s disease. Although more research is needed, one study
found that the diet helped improve symptoms of Parkinson’s disease
(34).
Polycystic ovary syndrome. The ketogenic diet can help reduce
insulin levels, which may play a key role in polycystic ovary
syndrome (35, 36).
Brain injuries. Some research suggests that the diet could improve
outcomes of traumatic brain injuries (37).
However, keep in mind that research into many of these areas is far from
conclusive.
Other health benefits of keto

8. SUMMARY
A ketogenic diet may provide many health benefits, especially
with metabolic, neurological, or insulin-related diseases.
Any food that’s high in carbs should be limited.
Here’s a list of foods that need to be reduced or eliminated on a
ketogenic diet:
sugary foods: soda, fruit juice, smoothies, cake, ice cream, candy,
etc.
grains or starches: wheat-based products, rice, pasta, cereal, etc.
fruit: all fruit, except small portions of berries like strawberries
beans or legumes: peas, kidney beans, lentils, chickpeas, etc.
root vegetables and tubers: potatoes, sweet potatoes, carrots,
parsnips, etc.
low fat or diet products: low fat mayonnaise, salad dressings, and
condiments
some condiments or sauces: barbecue sauce, honey mustard,
teriyaki sauce, ketchup, etc.
unhealthy fats: processed vegetable oils, mayonnaise, etc.
alcohol: beer, wine, liquor, mixed drinks
sugar-free diet foods: sugar-free candies, syrups, puddings,
sweeteners, desserts, etc.
SUMMARY
Avoid carb-based foods like grains, sugars, legumes, rice,
potatoes, candy, juice, and even most fruits.
Foods to avoid

9. You should base the majority of your meals around these foods:
meat: red meat, steak, ham, sausage, bacon, chicken, and turkey
fatty fish: salmon, trout, tuna, and mackerel
eggs: pastured or omega-3 whole eggs
butter and cream: grass-fed butter and heavy cream
cheese: unprocessed cheeses like cheddar, goat, cream, blue, or
mozzarella
nuts and seeds: almonds, walnuts, flaxseeds, pumpkin seeds, chia
seeds, etc.
healthy oils: extra virgin olive oil, and avocado oil
avocados: whole avocados or freshly made guacamole
low carb veggies: green veggies, tomatoes, onions, peppers, etc.
condiments: salt, pepper, herbs, and spices
It’s best to base your diet mostly on whole, single-ingredient foods. Here’s
a list of 44 healthy low carb foods.
SUMMARY
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Foods to eat

10. Base the majority of your diet on foods such as meat, fish, eggs,
butter, nuts, healthy oils, avocados, and plenty of low carb
veggies.
To help get you started, here’s a sample ketogenic diet meal plan for one
week:
Monday
breakfast: veggie and egg muffins with tomatoes
lunch: chicken salad with olive oil, feta cheese, olives, and a side
salad
dinner: salmon with asparagus cooked in butter
Tuesday
breakfast: egg, tomato, basil, and spinach omelet
lunch: almond milk, peanut butter, spinach, cocoa powder, and
stevia milkshake (more keto smoothies here) with a side of sliced
strawberries
dinner: cheese-shell tacos with salsa
Wednesday
breakfast: nut milk chia pudding topped with coconut and
blackberries
lunch: avocado shrimp salad
dinner: pork chops with Parmesan cheese, broccoli, and salad
Thursday
breakfast: omelet with avocado, salsa, peppers, onion, and spices
lunch: a handful of nuts and celery sticks with guacamole and salsa
A sample keto meal plan for 1 week

11. dinner: chicken stuffed with pesto and cream cheese, and a side of
grilled zucchini
Friday
breakfast: sugar-free Greek, whole milk yogurt with peanut butter,
cocoa powder, and berries
lunch: ground beef lettuce wrap tacos with sliced bell peppers
dinner: loaded cauliflower and mixed veggies
Saturday
breakfast: cream cheese pancakes with blueberries and a side of
grilled mushrooms
lunch: Zucchini and beet “noodle” salad
dinner: white fish cooked in olive oil with kale and toasted pine nuts
Sunday
breakfast: fried eggs with and mushrooms
lunch: low carb sesame chicken and broccoli
dinner: spaghetti squash Bolognese
Always try to rotate the vegetables and meat over the long term, as each
type provides different nutrients and health benefits.
For tons of recipes, check out these 101 healthy low carb recipes and this
keto shopping list.
SUMMARY
You can eat a wide variety of tasty and nutritious meals on a
ketogenic diet. It’s not all meats and fats. Vegetables are an
important part of the diet.
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12. In case you get hungry between meals, here are some healthy, keto-
approved snacks:
fatty meat or fish
cheese
a handful of nuts or seeds
keto sushi bites
olives
one or two hard-boiled or deviled eggs
keto-friendly snack bars
90% dark chocolate
full-fat Greek yogurt mixed with nut butter and cocoa powder
bell peppers and guacamole
strawberries and plain cottage cheese
celery with salsa and guacamole
beef jerky
smaller portions of leftover meals
fat bombs
SUMMARY
Great snacks for a keto diet include pieces of meat, cheese,
Healthy keto snacks

13. olives, boiled eggs, nuts, raw veggies, and dark chocolate.
Although getting started on the ketogenic diet can be challenging, there
are several tips and tricks that you can use to make it easier.
Start by familiarizing yourself with food labels and checking the
grams of fat, carbs, and fiber to determine how your favorite foods
can fit into your diet.
Planning out your meals in advance may also be beneficial and can
help you save extra time throughout the week.
Many websites, food blogs, apps, and cookbooks also offer keto-
friendly recipes and meal ideas that you can use to build your own
custom menu.
Alternatively, some meal delivery services even offer keto-friendly
options for a quick and convenient way to enjoy keto meals at
home.
Look into healthy frozen keto meals when you’re short on time
When going to social gatherings or visiting family and friends, you
may also want to consider bringing your own food, which can make
it much easier to curb cravings and stick to your meal plan.
SUMMARY
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Keto tips and tricks

14. Reading food labels, planning your meals ahead, and bringing
your own foods when visiting family and friends can make it
much easier to stick to the ketogenic diet.
Many restaurant meals can be made keto-friendly.
Most restaurants offer some kind of meat or fish-based dish. Order this
and replace any high carb food with extra vegetables.
Egg-based meals are also a great option, such as an omelet or eggs and
bacon.
Another favorite is bun-less burgers. You could also swap the fries for
vegetables instead. Add extra avocado, cheese, bacon, or eggs.
At Mexican restaurants, you can enjoy any type of meat with extra
cheese, guacamole, salsa, and sour cream.
For dessert, ask for a mixed cheese board or berries with cream.
SUMMARY
When eating out, select a meat-, fish-, or egg-based dish. Order
extra veggies instead of carbs or starches, and have cheese for
dessert.
Tips for eating out on a ketogenic diet
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15. Although the ketogenic diet is usually safe for most healthy people, there
may be some initial side effects while your body adapts.
There’s some anecdotal evidence of these effects often referred to as the
keto flu (38). Based on reports from some on the eating plan, it’s usually
over within a few days.
Reported keto flu symptoms include diarrhea, constipation, and vomiting
(39). Other less common symptoms include:
poor energy and mental function
increased hunger
sleep issues
nausea
digestive discomfort
decreased exercise performance
To minimize this, you can try a regular low carb diet for the first few
weeks. This may teach your body to burn more fat before you completely
eliminate carbs.
A ketogenic diet can also change the water and mineral balance of your
body, so adding extra salt to your meals or taking mineral supplements
may help. Talk to your doctor about your nutritional needs.
At least in the beginning, it’s important to eat until you’re full and avoid
restricting calories too much. Usually, a ketogenic diet causes weight loss
without intentional calorie restriction.
SUMMARY
Many of the side effects of starting a ketogenic diet can be
Side effects and how to minimize them

16. limited. Easing into the diet and taking mineral supplements can
help.
Staying on the keto diet in the long term may have some negative effects,
including risks of the following:
low protein in the blood
extra fat in the liver
kidney stones
micronutrient deficiencies
A type of medication called sodium-glucose cotransporter 2 (SGLT2)
inhibitors for type 2 diabetes can increase the risk for diabetic
ketoacidosis, a dangerous condition that increases blood acidity. Anyone
taking this medication should avoid the keto diet (40, 41).
More research is being done to determine the safety of the keto diet in
the long term. Keep your doctor informed of your eating plan to guide
your choices.
SUMMARY
There are some side effects to the keto diet about which you
should speak to your doctor if you plan to stay on the diet long
term.
Risks of the keto diet
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17. Although no supplements are required, some can be useful.
MCT oil. Added to drinks or yogurt, MCT oil provides energy and
helps increase ketone levels. Shop for MCT oil online (42, 43).
Minerals. Added salt and other minerals can be important when
starting out due to shifts in water and mineral balance (44).
Caffeine. Caffeine can have benefits for energy, fat loss, and
performance (45).
Exogenous ketones. This supplement may help raise the body’s
ketone levels (46).
Creatine. Creatine provides numerous benefits for health and
performance. This can help if you are combining a ketogenic diet
with exercise (47).
Whey. Use half a scoop of whey protein in shakes or yogurt to
increase your daily protein intake (48, 49). Shop for tasty whey
products on online.
SUMMARY
Certain supplements can be beneficial on a ketogenic diet.
These include exogenous ketones, MCT oil, and minerals.
Here are answers to some of the most common questions about the
ketogenic diet.
1. Can I ever eat carbs again?
Supplements for a ketogenic diet
Frequently asked questions

18. Yes. However, it’s important to significantly reduce your carb intake
initially. After the first 2 to 3 months, you can eat carbs on special
occasions — just return to the diet immediately after.
2. Will I lose muscle?
There’s a risk of losing some muscle on any diet. However, protein intake
and high ketone levels may help minimize muscle loss, especially if you
lift weights (50, 51).
3. Can I build muscle on a ketogenic diet?
Yes, but it may not work as well as on a moderate carb diet (52, 53). For
more details about low carb or keto diets and exercise performance, read
this article.
4. How much protein can I eat?
Protein should be moderate, as a very high intake can spike insulin levels
and lower ketones. Around 35% of total calorie intake is probably the
upper limit.
5. What if I am constantly tired, weak, or fatigued?
You may not be in full ketosis or be utilizing fats and ketones efficiently.
To counter this, lower your carb intake and revisit the points above. A
supplement like MCT oil or ketones may also help (42, 43).
6. My urine smells fruity. Why is this?
Don’t be alarmed. This is simply due to the excretion of by-products
created during ketosis (54).
7. My breath smells. What can I do?
This is a common side effect. Try drinking naturally flavored water or
chewing sugar-free gum.
8. I heard ketosis was extremely dangerous. Is this true?
People often confuse ketosis with ketoacidosis. Ketoacidosis is
dangerous, but the ketosis on a ketogenic diet is usually fine for healthy

19. people. Speak to your doctor before starting any new diet.
9. I have digestion issues and diarrhea. What can I do?
This common side effect usually passes after 3 to 4 weeks. If it persists,
try eating more high fiber veggies (55, 56).
A ketogenic diet can be great for people who:
are overweight
have diabetes
are looking to improve their metabolic health
It may be less suitable for elite athletes or those wishing to add large
amounts of muscle or weight.
It may also not be sustainable for some people’s lifestyles and
preferences. Speak with your doctor about your eating plan and goals to
decide if a keto eating plan right for you.
Read the article in Spanish.
Last medically reviewed on October 21, 2020
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