All about ketogenic diet & 3 day plan to get started

Written by Marina Lommel
20 minutes reading time
17. July 2023

Even before I launched Foodpunk in 2015, I had been studying ketogenic nutrition for many years. My final thesis was also about this. The ketogenic diet is a very effective diet. Unfortunately, there are many misunderstandings and misinformation circulating especially on the net. That’s why I’ve clearly summarized the most important basics about the ketogenic diet for you here.

Table of contents

    1. what is ketogenic diet?

    The ketogenic diet is a special form of alow-carbohydrate (low carb) diet. This form of nutrition is defined by the fact that special molecules are created in the body: The ketone bodies2.

    Definition of ketogenic diet: A ketogenic diet is defined by the fact that ketone bodies are formed by this diet. It is “ketogenic” – “ketone body generating“.

    Decisive criteria for a ketogenic diet4:

    • Very low carbohydrate diet
    • Insulin secretion minimal
    • Fat burning greatly increased
    • Liver produces ketone bodies from fatty acids

    2. what is ketosis?

    Ketosis is the metabolic state in which there is an increased amount of ketone bodies in the blood4.

    Definition of ketosis: a metabolic state in which the concentration of ketone bodies in the blood is elevated above normal.

    At this ketone body concentration in the blood, one speaks of ketosis1:

    • < 0.2 mmol/l no ketosis (= normal value)
    • 0.2-0.5 mmol/l light ketosis
    • 0.5-3.0 mmol/l ketosis (achievable through ketogenic diet)
    • 3.0-6.0 mmol/l ketosis (achievable by strict ketogenic diet, fasting or addition of MCT oil).

    Here you can read again in detail the definition of ketone bodies.

    3. what are ketone bodies?

    Ketone bodies are special molecules. They are produced in the liver from fatty acids and serve as energy carriers. The brain, muscles and other tissues can break down the ketone bodies and obtain energy from them.4

    The 3 ketone bodies are:

    • Beta-hydroxybutyrate
    • Acetoacetate
    • Acetone

    The ketone body acetone is exhaled via the breath. The other two ketone bodies serve as an energy source and can be converted into each other.

    Ketone bodies are water-soluble and can therefore be transported through the blood particularly well. They can cross the blood-brain barrier via special transporter channels and are thus absorbed into the brain, where they provide energy.4

    The exact pathway by which ketone bodies are produced in the liver is described in the linked article.

    In the article“How do ketone bodies become energy?” you can read how they are broken down in individual tissues – for example, muscles or brain – to produce energy.

    4. is ketosis a diet?

    “Ketosis” in itself is not a diet. It is “only” a metabolic state in which there are more ketone bodies in the blood than normal. The “ketogenic diet” or “ketogenic diet” is, of course, a diet. However, the word “diet” means nothing other than “diet”. A diet is not always a weight loss cure. There may also be medical diets. For example, the ketogenic diet is used to treat childhood epilepsy. More than 100 years ago, the ketogenic diet was developed for this very purpose. Find out who invented the ketogenic diet in one of our articles.6,10

    Even if the word “diet” does not always mean “weight loss diet”: one advantage of the ketogenic diet is that it allows you to lose weight very easily.

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    5. what are the advantages of the ketogenic diet?

    The ketogenic diet has numerous advantages. By giving up a lot of carbohydrates, the metabolism is rearranged. The body learns to use fat and ketone bodies as an energy source instead of carbohydrates and sugar.8

    Insulin levels are very low, which is why fat cells release fatty acids very readily. These fatty acids can then be burned directly by the muscles or converted to ketone bodies in the liver.8

    Benefits of the ketogenic diet:

    • Low blood glucose fluctuations5
    • Constant low insulin level2
    • High fat burning7
    • Improved fat metabolism8
    • Improved endurance performance7
    • Ketone bodies as an energy source for the brain4
    • Less cravings5
    • Increased feeling of fullness5
    • Fewer concentration fluctuations9

    These are just some of the benefits of the ketogenic diet. Through various mechanisms it supports a decrease but also an increased well-being. The ketogenic diet can have an anti-inflammatory effect, improving a bloated face and skin blemishes. Ketone bodies can have a neuroprotective effect in the brain – i.e. they protect nerve cells – and thus positively influence the course of individual diseases.1,8,9

    In individual articles we will go into more detail about the mechanisms of these benefits. In the article“Ketogenic diet in glucose transporter defect, you can read about the use of the ketogenic diet in a specific brain disease.

    6. what can I eat with keto?

    How many carbohydrates can I eat on keto?

    The amount of carbohydrates allowed on a ketogenic diet is individual. Even though it is often said: The amount of carbohydrates does not define a ketogenic diet. You often read “Keto, that’s less than 20 grams of carbohydrates” or “Keto, that’s less than 5% carbohydrates”. While it is true that you must lower your carbohydrate intake, that alone is not the definition of the ketogenic diet, but a means to an end. It’s a rough rule of thumb that can be very helpful in everyday life, but it’s not set in stone. A diet can be ketogenic even with 30 g of carbohydrates or 50 g of carbohydrates – as long as it stimulates the production of ketone bodies in you individually.1,8

    A good way to start is to limit carbohydrates to 30 grams per day and split those 30 grams over 3 meals. For example, 6 g in the morning, 12 g at noon and 12 g in the evening.

    How much protein can I eat on keto?

    A ketogenic diet is definitely not a high protein diet. It cannot be compared to a low carb high protein diet.

    During digestion, protein is broken down into its individual components – the amino acids. These amino acids are then incorporated into the body’s own structures, e.g. the muscles. If more amino acids are taken in than the body needs, they are metabolized into energy and “burned”. For this purpose, amino acids are first converted into glucose – sugar! In this way, excess protein also increases blood glucose and insulin levels and impedes ketosis.4

    15-20% protein in your diet is a good guideline – depending on how athletic you are, what your total energy needs are, and if you’re looking to lose weight.

    You should not go below 0.8 grams of protein per kg of body weight. But you don’t have to (and shouldn’t) eat a 300 g turkey steak at every meal like a bodybuilder.

    How much fat should I eat on keto?

    Fat is your main source of energy in a ketogenic diet. It is often claimed that more fat leads to more ketosis and higher fat burning, and that you lose weight even better with more fat in your diet. Not quite.

    Ketosis occurs because you are consuming low carbohydrates and moderate protein. The body can now either absorb the fat through food or release it from your fat cells.

    “So I can just cut out fat altogether and just consume the necessary amount of carbohydrates and protein and lose weight NO Faster?”. No, it’s not that simple.

    Let’s say you eat 30 g of carbohydrates per day and you have a total energy requirement of 2000 kcal. If you now consume 15% protein, that’s 75 g per day. 30 g of carbohydrates and 75 g of protein add up to 420 kcal. Really little.

    To avoid slipping into a harmful calorie deficit, you need to eat high-quality fats at every meal – and more than you might be used to. To get to the 2000 kcal, you would need to consume 1580 kcal in the form of fat, which is 175 g per day.

    Fat is an important basis for your hormone production and essential for the brain to notice that you are well supplied with energy. If you were to eat only 1200, 1000, or fewer calories per day, it signals starvation to your brain and it curbs your metabolism. Although you eat less, you lose weight worse.

    Especially at the beginning of the changeover, the release of fatty acids from the body’s own fat reserves is very slow. However, free fatty acids are necessary to establish stable ketosis, because fatty acids are the starting material for ketone bodies. That’s why, especially in the beginning, your ketosis benefits from the fatty acids you take in from the outside with your food. These are also partially converted to ketone bodies in the liver, and your body can train to produce and process ketone bodies even before your own fat burning is fully underway.

    We use here colloquially the term calories, scientifically correct are of course “kilocalories” and the corresponding abbreviation kcal.
    Now you know how to calculate how the meals should be composed. But: Every person is different and every metabolism works differently. So you may get into ketosis the same way with more carbs, or someone else may have to eat even fewer carbs to get the same result. Therefore, if necessary, the only thing that helps is to measure whether or how deeply you have entered ketosis as a result of your dietary changes. You can read about how to do this in the section “How can I measure ketosis?”

    What foods am I allowed to eat on keto?

    In a healthy ketogenic diet, vegetables should play the main role. Especially green vegetables contain so few carbohydrates that you can eat large amounts here without affecting your ketosis. You should avoid root vegetables on a ketogenic diet because of their high carbohydrate content. You should enjoy red and yellow vegetables like peppers and carrots in moderation. You can read detailed information about the carbohydrate content in vegetables in our article“This is how much vegetables the keto diet really contains!“. Besides vegetables, of course, you need a certain amount of protein. This promotes satiety and is crucial for maintaining muscle. High-quality protein from animal sources – eggs, fish, meat – is ideal. For a stable ketosis it is helpful to avoid dairy products in the beginning, because they cause a higher insulin release than fish or meat. When it comes to fish or meat, go for fattier varieties in particular. Because fat will be your main source of energy. High-quality fatty acids from coconut oil, avocado, olive oil, butter (lard) – from pasture milk or nuts (especially macadamias) are ideal.3

    For an overview of the best sources of fat, see the linked article.

    As a vegetarian, you should pay special attention to the quality of dairy products. Goat milk products are often better tolerated than cow milk products. Always reach for the full-fat varieties and pay attention to the amount of carbohydrates. Pure milk or even light yogurt contain relatively high amounts of carbohydrates – so you’ll quickly reach the 30 g per day. It is therefore a good idea to avoid carbohydrates directly, preferring to consume the permitted carbohydrates in the form of vegetables. In order to supply your body with sufficient protein and at the same time low carbohydrate intake, the use of protein powders is possible. Protein powders with a high biological value and availability of all essential amino acids are particularly suitable.

    Briefly explained: Protein consists of several amino acids, which are divided into essential and non-essential. The essential amino acids cannot be synthesized by the body itself, so that a sufficient supply through the diet is necessary. The essential amino acids include:

    • Histidine
    • Isoleucine
    • Leucine
    • Lysine
    • Methionine
    • Phenylalanine
    • Threonine
    • Tryptophan
    • Valine

    Foodpunk Whey protein has a high content of essential amino acids and has a high biological availability. With 1-3 tablespoons (10-30 g) you can palatably take 9-27 g of protein in the form of a shake or in a bowl.

    Leckere Eiweißquelle für Vegetarier und Veganer: Avocado Mousse au Chocolat – ein Rezept aus dem Foodpunk Ernährungsplan.

    As a vegan, you should reach for high-quality protein powders without additives. Suitable are, for example, almond protein, pumpkin seed protein or hemp protein. Even though we generally advise against soy products, fermented soy products are one way to get enough protein as a vegan. Fermented soy products (e.g. tempeh or natto) do not provide the same negative properties as unfermented soy products (tofu, tofu wieners…).

    You should see fruit as nature’s candy and consume it only in moderation. The best fit in a ketogenic diet are all kinds of berries. In our article“So much fruit you can eat on the keto diet” you will find a list with the carbohydrate contents of the different types of fruit.

    To show you at a glance which food groups should be the basis of your diet, and which are rather the exceptions, we have created a pyramid for you.

    The base is the very low-carbohydrate foods at the bottom. Above that, and also the basis of your diet should be the protein and fat-rich products, such as fish, meat, cheese or avocado. In limited quantities, the foods of the third group, i.e. nuts, berries and also yogurt/quark may be consumed. The top of the pyramid and thus the least represented in terms of quantity are the exceptions, i.e. the foods that should only be consumed in small quantities, such as: dark chocolate, some types of fruit, but also so-called low-carbohydrate “replicas”, such as the Lower Carb grain bread Hemp Bread.

    Not suitable for a ketogenic diet are:

    • Cereals (pasta, oatmeal, pizza, bread…)
    • Potatoes
    • Sugar
    • Sugary drinks
    • Juices and juice spritzers
    • Sweets

    7. 3 day plan for fast ketosis

    For a super quick start into ketosis, you can follow this plan:

    Day 1: Empty carbohydrate stores

    • Radically eliminate sources of carbohydrates (fruit, pasta, juices…)
    • On the plate: 2/3 green vegetables, 1/3 high quality protein source, 1-2 tbsp coconut oil.
    • Evening: 60 minutes of strength training until exhaustion

    Day 2: Form ketone bodies

    • Morning: 60 minutes endurance training, moderate
    • Breakfast: 3 eggs, 20 g pasture butter, 200 g cucumber, 1 tbsp MCT oil
    • Lunch / dinner: 2/3 green vegetables, 1/3 high quality protein source, 1-2 tbsp coconut oil.

    Day 3: Boost ketosis

    Morning: butter coffee with 20 g pasture butter, 1 tbsp MCT oil

    4-5 hours break between meals

    Lunch / dinner: 2/3 green vegetables, 1/3 high quality protein source, 1-2 tbsp coconut oil.

    8. how can I measure ketosis?

    To start, it is recommended to measure ketosis to get a good sense of what ketosis feels like. If you’ve been in ketosis for a few months, you’ll know when you’re “in” even without measuring.1

    There are 3 methods for classical measurement:

    • Measurement of ketone bodies in urine
    • Measurement of ketone bodies in the blood
    • Measurement of ketone bodies in the breath

    The measurement in urine is the cheapest, because the test strips are not too expensive in the pharmacy. However, only those ketone bodies that the body has excreted are detected in the urine. The better the body can utilize ketone bodies for energy, the fewer ketone bodies are excreted in the urine.3

    Thus, as ketoadaptation increases, the concentration in urine decreases.

    Measuring the blood concentration is more reliable and always gives an accurate picture of how high the ketone body concentration actually is. Therefore, I recommend a blood ketone meter, which works like a blood glucose meter. There are combination devices for blood glucose and blood ketone concentration with special test strips for ketosis measurement.

    Die Verwendung eines Blutzuckermessgerätes mit Ketose-Teststreifen ist eine verlässliche Methode zur Bestimmung der Ketonkonzentration im Blut.

    Advanced users and those interested in long-term regular measurement of ketosis can turn to a breath ketone meter: a device that measures the concentration of acetone in the breath and thus can make inferences about blood ketone body concentration. Due to the high initial cost, it is definitely a device for an advanced application.3

    Tip: If you use Ketostix, you can cut the test strips in half lengthwise and get twice as many readings for the same money.

    9. is ketosis ketoacidosis?

    In the study of medicine or nutrition science, ketosis is addressed only in passing. Most of the time, you only discuss ketoacidosis. This leads many professionals to equate the two. However, healthy (physiological) ketosis is not at all the same as ketoacidosis.

    In a healthy person with a functioning pancreas and normal insulin secretion, ketone bodies always attract a little insulin. Higher insulin levels cause ketone bodies to be excreted in the urine. In this way, the insulin keeps the ketone body concentration within healthy limits.

    Only when this natural regulatory mechanism no longer functions can the values rise sharply. This risk is present in type I diabetes and alcoholisums – and not only with a ketogenic diet. Type I diabetics must always maintain a proper balance of sugar or carbohydrate consumption and insulin administration to avoid harmful hypoglycemia and the development of ketoacidosis.3

    However, if you have your values and insulin dose under control, you can also follow a ketogenic diet as a type I diabetic.

    At this ketone body concentration in the blood, ketoacidosis is present: 15-25 mmol/l ketoacidosis (not possible in healthy people, only in type I diabetes and alcoholism).

    10. where can I find a diet plan for the ketogenic diet?

    Foodpunk founder Marina has been involved with ketogenic nutrition for 8 years and since 2015 has been offering nutrition programs on Foodpunk that are calculated to meet personal needs. Meanwhile, a team of nutritionists supports all participants. Learn more about the staff at Foodpunk.

    Thousands of customers have been accompanied by Foodpunk on their individual journey since its inception. In addition to weight loss, it is often about alleviating symptoms of conditions such as lipedema, ulcerative colitis, allergies and intolerances. The successes awakened the desire to also prove in studies what the ketogenic diet can do, so the cooperation with various doctors and clinics was born. All these experiences and the extensive knowledge of Marina are now also recorded in 5 books. Foodpunk has also received numerous awards: At Anuga 2019, we received the award for top innovations for the low carb bread alternative hemp bread. But as a company, we also landed in 6th place among the Top 50 Startups of 2018.

    You would also like to benefit from the numerous experiences and maybe share a success story with us one day? Then you’ve come to the right place. We support you and write you an individual nutrition plan with delicious recipes that you can open directly in the app or on the internet.

    11. where can I find recipes for the ketogenic diet?

    On the Foodpunk blog, you’ll find plenty of tasty ideas in the Keto category. Over time, you’ll learn very easily how to transform your favorite dishes in an uncomplicated way. Often it is enough to replace the carbohydrate side dish with vegetables. For example, how about vegetable pasta or a lasagna with zucchini plates? Burgers also turn out wonderfully without a bun. Try this delicious eggplant halloumi burger, our turkey spinach bur ger, or – for fish lovers – the Foodpunk salmon burger, where the burger buns are made with Portobello mushrooms. You can even recreate sweet sins with keto-friendly ingredients.

    Our top 10 sweet keto cuisines from the blog are:

    1. Vegan chocolate mousse
    2. White Chocolate Macadamia Blondie
    3. Keto strawberry curd with sweet walnut
    4. Keto Nougat Chocolate
    5. Keto caramel toffees
    6. Keto Cookie Dough with MCT Powder
    7. Foodpunk Panna Cotta
    8. Ketogenic Strawberry Tiramisu with Vanilla Heaven Bisquit
    9. Ketogenic Foodpunk Slice with Sweet Sin
    10. Keto nut nougat shake

    You’ll find even more ideas in the Foodpunk app – all tailored for you and your individual needs and food preferences. Keto has never been so easy.

    In unserer Foodpunk App findest du eine große Auswahl sowohl herzhafter als auch süßer Gerichte.

    12. Who is the ketogenic diet suitable for?

    For whom is the ketogenic diet not suitable?

    Patients with the following conditions should be sure to talk to their doctor before starting a ketogenic diet1:

    • Hyperinsulinism
    • Pyruvate carboxylase deficiency
    • Fatty acid oxidation disorders
    • Acute porphyria

    For whom is the ketogenic diet particularly well suited?

    • Patients with well-controlled diabetes
    • People who want to reduce their weight
    • Patients with high cholesterol and/or triglyceride levels
    • Patients with epilepsy, can benefit from your ketogenic diet8

    13. experience with ketogenic diet

    You have already tried the ketogenic diet and also spent some time in ketosis? We are eager to hear about your experiences. Leave us a comment and tell us about your keto story. What are your favorite recipes? How do you implement keto in your stressful everyday life or away from home? Do you measure ketosis and if so, how? In the linked article, Martina and Nanette share their experiences with keto nutrition. Numerous other testimonials from our customers can be found on our website.


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    14. common questions about the ketogenic diet

    Can I never eat bread again?

    The question of how long to follow a ketogenic diet always depends on the reason and goal of the dietary change. Since it takes a few days for the body to adjust to the new metabolic situation, you should take at least 4 weeks to try this diet.

    Being in ketosis all the time is virtually impossible, as a few “more” carbohydrates are quickly consumed. This is not a bad thing either, as the goal is to restore or even improve the body’s metabolic flexibility. For example, even after a ketogenic phase, you can switch to the moderate low-carb phase, where you can eat a few more carbs.3

    But here’s another tip: If you’re hungry for a slice of bread, you don’t have to give up the ketogenic diet right away. Try one of the delicious bread baking mixes from our store.

    Does the ketogenic diet also go vegetarian/vegan?

    If you abstain from meat or animal products, this is not an exclusion criterion for the ketogenic diet. It is important for you to make sure that you eat enough protein. With our Whey Protein Powder, you can create delicious high-protein vegetarian dishes from our app. For the vegans we have hemp or pumpkin seed protein in the store and delicious recipes for it in the blog. How about a Vegan Chocolate Mousse, for example? You can enrich this super with 1-2 tablespoons of portein powder.

    Is the ketogenic diet suitable for muscle building?

    If you pay attention to adequate protein intake and engage in regular muscle-building training, a ketogenic diet will not limit muscle growth. Recent studies show that the ketogenic diet is an effective method for body fat loss and muscle building.11

    What is the difference between ketogenic and Paleo?

    Paleo or also known as Paleo diet is the so-called Stone Age diet. The idea behind this is that the human body can best metabolize the foods that were eaten by Stone Age people. Industrially produced foods such as bread, refined sugar, etc. were of course not part of the diet of prehistoric man. However, Paleo foods are not always ketogenic at the same time, such as the banana. On the other hand, a baking mix for ketogenic bread is certainly not suitable for a Paleo diet.

    Always stay up to date with our Newsletter.

    Are you now also in the mood for a ketogenic diet plan with delicious recipes, which is adapted exactly to you, your values and goals? Then start now and discover your new life full of energy and pleasure!


    Cover photo: Oleksandra Naumenko(

    Further reading:

    1. Bahr, LS et al: The ketogenic diet – what it can do, how it works and how it succeeds; in: ZKM 2018: 2: 22-29

    2. Gupta, L. et al, Ketogenic diet in endocrine disorders: current perspectives; in: J Postgrad Med. 2017 Oct-Dec; 63(4): 242-251.

    3. Gonder, U. Et al.: The Keto Compass, 2019, Systemed Verlag, Munich.

    4. Horn, F. et al: Biochemie des Menschen: The Textbook for Medical Studies, Thieme, Stuttgart, 3rd ed.

    5. Johnstone, AM. et al: Effects of a high-protein ketogenic diet on hunger, appetite, and weight loss in obese men feeding ad libitum, in: Am J Clin Nutr 2008; 87: 44-55.

    6. Klepper, J. et al: The ketogenic diet in German-speaking countries in 2003: a status review; in: Klein Pediatr 2004; 2016: 277-285.

    7. McSwiney, FT, et al: Keto-adaptation enhances exercise performance and body composition responses to training in endurance athletes; in: Metabolism Clinical Experimental 81 (2018) 25-34.

    8. Paoli A. Et al: Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets, in: European Journal of Clinical nutrition: 2013; 67, 789-796.

    9 Takeishi, J. Et al: Alzheimer’s Disease and Type 2 Diabetes mellitus: The use of MCT Oil and a ketogenic diet; in: Int. J. Mol. Sci. 2021, 22, 12310

    10. Wheless, JW: History of the ketogenic diet; in: Epilepsy, 2008: 49 (Supp. 8): 3-5

    11. Paoli, A. Et al: Effects of two months of very low carbohydrate ketogenic diet on body composition, muscle strength, muscle area, and blood parameters in competitive natural body builders; in: Nutrients 2021, 13, 374

    This article was written by

    Marina Lommel

    Marina gründete Foodpunk nach ihrem Abschluss in Ernährungswissenschaften und ist aktuell CEO des Unternehmens. Während ihres Studiums arbeitete sie in verschiedenen Bereichen, darunter in der Wissenschaftsredaktion beim Radio, Redaktion beim TV und Uni-Wissensmagazin sowie im Labor am DZNE in der Parkinsonforschung. Marina ist außerdem Autorin von 5 ernährungswissenschaftlichen Sachbüchern.

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