The Ketogenic Diet: Everything You Need to Know to Start the Keto Diet

The Ketogenic Diet: Everything You Need to Know to Start the Keto Diet

The purpose of the ketogenic diet is to force the body into burning fats instead of carbohydrates. Here are the basics you need to know to succeed on keto.


If you could train your body to burn fat, would you? Of course you would. Fortunately, that’s what the keto diet is all about — burning fat, rather than glucose, for energy.

The ketogenic diet is a high-fat, low-carb diet. And over the past few years, keto has grown in popularity as people recognize how efficiently it can help you reach your health and fitness goals.

If you’re new to the keto diet, you probably searched “How to start keto diet” and landed on this page. You’re also probably wondering, “What is the ketogenic diet all about, and can it work for me?” This page is your ultimate guide to all your toughest keto questions from “what is keto” to “what can I eat” and “how can I avoid the keto flu?”

First thing’s first: What is the keto diet? Before you jump into the motivation stage, you should learn what this diet is all about.

What Is the Ketogenic Diet?

The ketogenic diet, or “keto,” is a high-fat, low-carb diet that puts your body in a fat-burning state known as ketosis. In ketosis, your body burns body fat, rather than carbohydrates, for fuel.

You get into ketosis by cutting your carbohydrate intake. Many people think of the keto diet as a super high-fat diet. But consuming massive amounts of fat isn’t nearly as important as cutting carbs when it comes to changing your metabolism to run off fat for fuel.

To fully understand this metabolic shift, it’s important to understand your metabolism works.

How Does the Keto Diet Work?

When you eat a diet rich in carbohydrates, your body converts those carbs into glucose (blood sugar). Since carbohydrates are turned into sugar, your blood sugar levels rise.

When blood sugar levels rise, it signals your body to create insulin, which carries glucose to your cells to be used for energy[*]. This is what is known as an “insulin spike.”

Glucose is your body’s preferred energy source. As long as you keep eating carbohydrates, your body will keep turning it into sugar, thereby burning that sugar for energy. In other words, when glucose is present, your body will refuse to burn off its fat stores.

Since carbs are your body’s preferred energy source, the only way to start burning fat is by removing carbs.

Cutting carbs depletes your glycogen stores (stored glucose)[*]. And with no glucose available for energy, your body has no choice but to start burning its fat stores. Your body starts converting fatty acids into ketones, a metabolic state known as ketosis, and the basis of a ketogenic diet.

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What Are Ketones?

For more information on this topic, see the full article.

In ketosis, your liver converts fatty acids into ketone bodies or ketones. These byproducts become your body’s new energy source. When you decrease your carb intake and replace those calories with healthy fats and carbs, your body responds by becoming “keto-adapted,” or more efficient at burning fat.

Think ketosis isn’t “natural”? Think again!

Your body was made to switch in and out of ketosis, which is a natural function of the human body.

Ketosis helps your body function on stored body fat when food is not readily available. Similarly, the keto diet focuses on “starving” your body of carbohydrates, switching you into a fat-burning state.

The three main ketone bodies produced in the liver are:

  • Acetoacetate (AcAc)
  • Beta-hydroxybutyric acid (BHB)
  • Acetone

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The Difference Between Keto, Low-Carb, and Atkins

For more information on this topic, see the full article.

Too often, the keto diet gets lumped in with other low-carbohydrate diets, like the Atkins Diet. There are a few key differences between them.

Difference in Carbohydrate Intake

The main difference between keto and low-carb is the macronutrient levels. Low-carb diets are considered any diet with a total carb intake under about 100-150 grams of carbs per day. It’s likely that you’ll have to lower your carb intake much more to enter a state of ketosis.

The Atkins Diet is different from keto because of its different phases, which range from severely restricting carbs to adding a liberal amount of carbs (about 80-100 grams daily) back into the diet.

The keto diet works best when you stick to consistently low-carb intake — under about 50 grams per day for most people.

Difference in Protein Intake

Most low-carb diets are also high-protein diets. However, the keto diet ranges in protein intake, from moderate (around 20% of your total calories) to high-protein intake.

Unlike Atkins, the keto diet is not associated with high-protein intake. Instead, keto focuses on moderate protein, low-carb veggies, and quality fats.

If you’re unsure of your optimal protein intake, check out the Keto Calculator to get your unique macronutrient guidelines.

Difference in Goals

The goals between these diets vary as well. Unlike Atkins, paleo, or the Mediterranean diet, the goal of keto is to enter ketosis, weaning your body off burning glucose for fuel for the long-term.

You may never enter ketosis with a low-carb diet. And although you may enter ketosis for a brief period on the Atkins Diet, you’ll pop right back out in Phases 3 and 4 as you reintroduce higher levels of carbohydrate-rich foods.

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Ketogenic Diet Macronutrients

Macronutrients seem to be the cornerstone of any keto diet, but contrary to popular opinion, there is no single macronutrient ratio that works for everyone.

Instead, you’re going to have a completely different set of macros than your friend or your mother based on:

  1. Your physical and mental goals
  2. Your health history
  3. Your activity level

The best way to figure these numbers out quickly is to refer to this macronutrient calculator.

Outside of your personal macros, there are general macro guidelines for a ketogenic diet:

  • 70-80% of calories from fats
  • 20-25% of calories from protein
  • 5-10% of calories from carbohydrates

Below, these percentages are broken down into grams. Remember, these should be used as a guideline only. Your macronutrient goals will vary depending on your particular lifestyle.

But here are some general guidelines when it comes to macros that just about anyone can follow.

Fat Intake

Fat is known as the cornerstone of the keto diet because fat doesn’t raise your blood glucose like carbohydrates.

It was once thought that in order to get into ketosis, you needed to eat massive amounts of fat on a daily basis. However, that’s just not true.

The real secret to getting into ketosis is to cut carbs. You can modulate your fat intake from there. However, the accepted rule of thumb for most keto dieters is to stick to anywhere from 70–80% of your calories from healthy fats.

That means, if you’re consuming 2,000 calories per day, you would need 144 to 177 grams of fat.

Protein Intake

Protein has gotten a bad rap in the keto community. Some experts claimed that eating too much protein on a very low-carb diet could trigger a metabolic effect called gluconeogenesis.

But that’s not true, either.

Protein is extremely important on the keto diet — especially if you’re active or an athlete.

Ideally, you should consume at least 0.8 grams of protein per pound of lean body mass to prevent muscle loss. For those of you with an extremely active lifestyle, 1 gram of protein per pound of lean body mass is ideal.

To calculate your lean body mass, you have to:

  • Calculate your body fat percentage. Click here to read how.
  • Subtract your body fat % from 100%. This will be your lean body mass %.
  • Multiply your lean body mass % by your total weight.

Or, you can check out the Perfect Keto Macro Calculator to figure out your ideal protein intake. So while most keto sites recommend 10–15% of total calories from protein, know that you can eat a lot more without raising your blood glucose or kicking you out of ketosis.


Most people who want to get into ketosis should get about 5–10% of total calories from carbohydrates. This usually looks like anywhere from 100-200 calories from carbs or about 25–50 grams of carbohydrates per day.

Most people consume roughly 30 grams of carbohydrates on the keto diet. Depending upon your activity level and health needs, you might be able to consume up to 80 grams of carbs and remain in ketosis.

What are you waiting for? Start your keto diet now.

Different Types of Ketogenic Diets

For more information on this topic, see the full article.

There are five main approaches to the ketogenic diet. When deciding which method works best for you, take into account your goals, fitness level, and what’s realistic for your lifestyle.


This is the most common and recommended version of the diet. Here, you stay within 20–50 grams of net carbs per day, focusing on moderate protein intake and high-fat intake.

Note: The SKD method is the most used and researched version of keto. The majority of the information in this guide pertains to this standard method.


If you are an active individual, this approach might work best for you. Targeted keto involves eating roughly 25-50 grams of net carbs or less 30 minutes to an hour before exercise.


If keto seems intimidating to you, this is an excellent method to start with. You cycle between periods of eating a low-carb diet for several days, followed by a period of eating higher amounts of carbs (typically lasting several days).


This approach is very similar to the standard (SKD) approach. The primary difference is your protein intake. While a standard keto diet will include moderate protein, here you up your protein intake considerably.


Plant-based keto could range from eating more low-carb vegetables to going keto as a full-on vegan or vegetarian. You can follow the ketogenic diet as a vegetarian or vegan, but it will take a lot of effort and possibly the guidance of a professional physician or nutritionist to do so safely.

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What Can You Eat on a Keto Diet?

For more information on this topic, see the full article.
Now that you understand the basics behind the keto diet, it’s time to hit the grocery store.

On the keto diet, you’ll enjoy nutrient-dense foods including meat, vegetables, nuts and seeds, and plenty of healthy fats.

You’ll also avoid grains, legumes, processed foods, and most fruits. Consume these keto-friendly foods while staying within your macro guidelines:


All meat and seafood are included on the keto diet, as long as they’re not breaded or fried.

Always choose the highest quality meat you can afford, selecting grass-fed and organic beef whenever possible, wild-caught fish, and pasture-raised poultry, pork, and eggs.

Nuts and seeds are also fine and best eaten raw (not roasted or coated in sugar).


  • Beef, preferably fattier cuts like steak, veal, roast, ground beef, and stews
  • Poultry, including chicken breasts, quail, duck, turkey and wild game — try to focus on the darker, fattier meats
  • Pork, including pork loin, tenderloin, chops, ham, and sugar-free bacon
  • Fish, including mackerel, tuna, salmon, trout, halibut, cod, catfish, and mahi-mahi
  • Bone broth, including beef bone broth and chicken bone broth
  • Shellfish, including oysters, clams, crab, mussels, and lobster
  • Organ meats, including heart, liver, tongue, kidney, and offal
  • Eggs, including deviled, fried, scrambled and boiled — use the whole egg
  • Lamb
  • Goat
  • Vegetarian sources like macadamia nuts, almonds, and nut butter


On a keto meal plan, feel free to fill your plate with low-carb vegetables.

Vegetables are a great way to get a healthy dose of micronutrients, thus preventing vitamin deficiencies on keto.

Enjoy low-carb vegetables like leafy greens, and cruciferous veggies, aiming to eat veggies that contain fewer than 5 grams of net carbs per serving.

Enjoy these low-carb vegetables:

  • Leafy greens, such as kale, spinach, Swiss chard, and arugula
  • Cruciferous vegetables, including cabbage, cauliflower, and zucchini
  • Lettuces, including iceberg, romaine, and butterhead
  • Fermented vegetables like sauerkraut and kimchi
  • Other vegetables such as mushrooms, asparagus, and celery


If you can tolerate dairy, it is allowed on the keto diet. Choose the highest quality you can reasonably afford, selecting grass-fed, whole-fat, and organic dairy whenever possible. Avoid low-fat or fat-free dairy products, or products that have a high-sugar content.

Keto-friendly dairy options include:

  • Butter and ghee
  • Heavy cream and heavy whipping cream
  • Fermented dairy products like yogurt and kefir
  • Sour cream
  • Hard and soft cheeses


Approach fruit with caution on keto, as it contains high amounts of sugar and carbohydrates. If you’re craving something light and sweet, grab a handful of berries, such as blueberries or raspberries, as a treat.

Enjoy these low-sugar fruits:

  • Avocados (the one fruit you can enjoy in abundance)
  • Organic berries, such as raspberries, blueberries, strawberries, and cranberries


You can enjoy both animal fats (saturated fats) and plant-based fats on a healthy keto diet.

Healthy fat sources include grass-fed butter, tallow, and ghee or coconut oil, olive oil, sustainable palm oil, and MCT oil from plants.

Enjoy these fats and oils on keto:

  • Butter and ghee
  • Lard
  • Mayonnaise
  • Coconut oil, coconut butter
  • Flaxseed oil
  • Olive oil
  • Sesame seed oil
  • MCT oil and MCT powder
  • Walnut oil
  • Olive oil, avocado oil


Use seasonings freely on keto — just make sure they don’t have any added sugar. To add flavor to dishes, consider purchasing fresh herbs at the store.

Pro tip: If you store fresh herbs in a mason jar filled with water in the fridge, they will last up to two weeks.

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Foods to Avoid on a Keto Diet

For more information on this topic, see the full article.
It’s best to avoid the following foods on a keto diet due to their high carb content. When starting keto, do a purge of your fridge and cupboards. Donate any unopened items and throw the rest away.


Unfortunately, many standard American diets are centered on grains and other processed, high-carb foods. Grains are loaded with carbs, so it’s best to avoid all grains on keto. Whole grains, wheat, pasta, rice, oats, barley, rye, corn, and quinoa are all out. Instead, try one of these substitutes.


While many vegans and vegetarians rely beans for their protein content, they are actually incredibly high-carb. Avoid eating kidney beans, chickpeas, black beans, and lentils.


While many fruits are packed with antioxidants and other micronutrients, they’re also high in fructose, which will kick you out of ketosis.

Avoid apples, mangoes, pineapple, and other fruits (with the exception of small amounts of berries).


Avoid starchy vegetables like potatoes, sweet potatoes, some squash, parsnips, and carrots.

Like fruit, there are health benefits to these foods. However, you can find those vitamins and minerals from low-carb sources — ones that won’t kick you out of ketosis.


This includes, but is not limited to desserts, artificial sweeteners, ice cream, smoothies, soda, and fruit juice.

Even condiments like ketchup and BBQ sauce are usually filled with sugar, so put down the ketchup bottle. If you are craving a dessert, try one of these keto-friendly recipes, made with low glycemic sweeteners instead.


Some alcoholic beverages are low glycemic and appropriate for a ketogenic diet. However, keep in mind that when you drink alcohol, your liver will preferentially process the ethanol and stop producing ketones.

If you’re on a ketogenic diet to lose weight, keep your alcohol consumption to a minimum. If you’re craving a cocktail, stick to low-sugar mixers and avoid most beer and wine.


Seed oils are heavily processed and can become oxidized (aka, rancid) when you heat them. Avoid corn oil, canola oil, peanut oil, and grapeseed oil. They also contain large amounts of omega–6 fatty acids, which are inflammatory in large amounts.

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Health Benefits of a Keto Diet

A ketogenic diet has been associated with incredible health benefits that stretch way beyond weight loss. Here are just a few ways keto may help you feel better, stronger, and more clear-headed:


Probably what the keto diet is most famous for: sustainable fat loss. Keto can significantly decrease body weight, body fat, and body mass while maintaining muscle mass[*]. Keto can also increase fat metabolism during exercise, making it an excellent part of your active lifestyle[*].


The ketogenic diet may help improve endurance levels for athletes. However, it may take time for athletes to adjust to burning fat instead of glucose for energy[*].


Several studies have shown a link between low sugar intake and improvement in symptoms of irritable bowel syndrome (IBS). One study showed that eating a ketogenic diet can improve abdominal pain and overall quality of life in those with IBS[*].


The ketogenic diet helps to balance blood sugar and insulin levels. The decreased risk of insulin resistance can help prevent metabolic diseases like type 2 diabetes[*].


The keto diet can help reduce risk factors for heart disease, including improvement in HDL cholesterol levels, blood pressure, triglycerides, and LDL cholesterol (related to plaque in the arteries)[*].


The keto diet may support those with Parkinson’s, Alzheimer’s disease, and other degenerative brain diseases[*]. This is likely because ketone bodies having possible neuroprotective and anti-inflammatory benefits[*].


Because ketones and lower blood sugar contribute to overall hormone balance and lower inflammatory markers, the keto diet may be good for skin health. One study suggests that decreased skin inflammation can decrease acne and other skin lesions[*].


The ketogenic diet was created in the early 20th century to help prevent seizures in epileptic patients, especially children[*]. To this day, ketosis is used as a therapeutic diet for those who suffer from epilepsy.


There’s a growing body of research that suggests a strict keto diet can help slow tumor growth[*]. Although no one diet can cure or prevent cancer, a low-carb, zero-sugar diet is a great place to start.


An estimated 90% of women experience one or more symptoms associated with PMS[*][*]. A keto diet can help balance blood sugar, combat chronic inflammation, boost nutrient stores, and crush cravings — all of which may help alleviate PMS symptoms.

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How to Know When You’re in Ketosis

For more information on this topic, see the full article.
You can follow the above macronutrient guidelines, eat the prescribed keto diet foods, and avoid grains, starches, and legumes and still struggle to enter ketosis.

Why? Because ketosis is a metabolic state, and you may need to tweak your meal plan, exercise regimen, and other lifestyle choices in order to enter it.

How to Start Keto Diet: 5 Signs You're Fat-Adapted

There are plenty of signs and symptoms to suggest you’re in ketosis, including:

  1. Weight loss
  2. Fewer cravings
  3. Better mental clarity
  4. More stable energy

But there’s only one reliable way to know whether or not you’re in ketosis: Test your ketone levels.

There are three ways to do this:

  • In your urine with a urine strip
  • In your blood with a glucose meter
  • On your breath with a breath meter

How to Start Keto Diet: The Ketogenic Diet Heirarchy of Needs Testing

Each method has its advantages and disadvantages, with a blood test being the most accurate (but most expensive). Although it’s the most affordable, urine testing is typically the least accurate method.

For more information on this topic, see the full article.

Supplements to Support a Keto Diet

For more information on this topic, see the full article.

Most people can enter ketosis by eating a high-fat, low-carb diet, exercising regularly, or even experimenting with intermittent fasting. However, for the times when a more natural approach is not enough, you might want to consider using supplements to enter a ketogenic state.

Supplements are a popular way to maximize the benefits of a ketogenic diet. You can’t get all of your nutrients from supplements and expect to feel good, but they can help.

Add in these supplements alongside a healthy, whole-food based keto diet for the best results.

For more information on this topic, see the full article.


Exogenous ketones are supplemental ketones — usually beta-hydroxybutyrate or acetoacetate — that help give you the energy you need to thrive. You can take exogenous ketones in between meals or for a quick burst of energy before a workout.


MCTs (or medium-chain triglycerides) are a type of fatty acid that your body can convert to energy quickly and efficiently. Benefits include weight loss and energy, among other things. MCTs come from coconuts and are sold mostly in liquid form. Perfect Keto sells them as a delicious and easy-to-use powder.


Collagen is the most abundant protein in your body, accounting for about 25–35%. It’s the glue that holds your body together as it supports the growth of joints, organs, hair, and connective tissues. Amino acids from collagen supplements may also help with energy production, DNA repair, detox, and healthy digestion[*].


It’s tough to get all the micronutrients you need from diet alone — regardless of what nutrition regimen you’re on. Keto Micro Greens are the solution to getting all your micronutrients in one convenient scoop. Each serving contains 14 servings of 22 different fruits and vegetables, plus herbs and MCT fats to assist with absorption.


Keto pre-workout supplements like Perfect Keto Perform Pre-Workout can boost physical and cognitive performance without the caffeine crash. It contains exogenous ketones and MCT oil powder for energy, creatine for protein metabolism, branched-chain amino acids for muscle growth and repair, and more.


Protein supplements are some of the best-studied supplements for weight loss support, muscle gain, and recovery. Make sure to choose grass-fed whey only and avoid powders with sugar or any other additives that could spike blood sugar.


Electrolyte balance is one of the most critical — yet most overlooked — components of a successful ketogenic diet experience. A keto diet can make you excrete more electrolytes than usual so you have to replenish them yourself — a fact few know about when starting the keto diet[*]. Add more sodium, potassium, and calcium to your diet or grab a supplement that can help.


Get even more benefits of an anti-inflammatory keto diet with some high-quality omega-3 fatty acids. Krill oil is just as potent as fish oil, without the fishy aftertaste. Krill also contains phospholipids and a potent antioxidant called astaxanthin that fish oil doesn’t.


Think about adding vitamins, minerals, and herbs to support normal digestion, metabolism, hormone function, and energy production. Take these with higher carb meals to support healthy carbohydrate metabolism or just to promote healthy nutrient absorption.

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Is the Ketogenic Diet Safe?

For more information on this topic, see the full article.

Ketosis is a perfectly safe and natural metabolic state, but it is often confused with a highly dangerous metabolic state called ketoacidosis.

Having ketone levels in the 0.5-5.0mmol/L range is not dangerous, but other risks include a range of issues, from harmless keto flu symptoms to diabetic ketoacidosis, which is not a problem unless you’re diabetic.


Diabetic ketoacidosis (DKA) is a dangerous metabolic state that is most commonly seen in people with type 1 diabetes and sometimes type 2 diabetics if they aren’t properly managing their insulin and diet[*].


Many people deal with common short-term side effects similar to flu-like symptoms as they become fat adapted after decades of running on carbs. These temporary symptoms are byproducts of dehydration and low-carbohydrate levels while your body adjusts:

  • Headaches
  • Lethargy
  • Nausea
  • Brain fog
  • Stomach pain
  • Low motivation

The keto flu can often be shortened or avoided completely by taking ketone supplements, which help make the transition into ketosis much shorter and easier.

Get started with Perfect Keto’s Keto Kickstart

Get Started on Keto

Now that you understand the science behind keto, what foods to eat and what foods to avoid, you’re ready to get started.

Any new diet can be daunting, which is why Perfect Keto has so many resources to help you cook, shop, and meal prep on keto. To begin, try these resources:





Are you really ready to do this? Sign up for this 30-day program, designed to get you keto-adapted, losing weight, and gaining muscle in just 30 days.

If you’ve tried the ketogenic diet before and didn’t make it past a few days or weeks, this guided program is for you. If you’re on a keto diet right now and have hit a slump or plateau, try this program.

The Keto Kickstart includes:

  • Tips and tools on how to get into and stay in ketosis
  • Shopping lists
  • Easy, family-friendly recipes
  • Easy lessons on how ketosis actually works
  • Learn how to figure out if you’re in ketosis and track your progress

It’s the mission at Perfect Keto to make your keto journey as enjoyable as possible. Health doesn’t have to be hard. Join now!

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