A ketogenic diet is a weight loss method that puts your body into a metabolic state called ketosis. When this happens, the body uses fat instead of carbohydrates (or sugars) for energy. Because no carbohydrate exists in the blood, the liver converts them into fatty acids (beta-hydroxybutyrate), which are used for fuel.
This change causes insulin and glucose levels in the blood to become unbalanced. Glucose leads to an increase in insulin, and insulin increases the amount of glucose stored by cells. However, when there's not enough glucose available to meet cellular needs, the body starts breaking down its own muscle tissue into sugar (gluconeogenesis). As a result, the person loses water and potassium while retaining sodium and chloride.
This process can lead to severe dehydration, fatigue, weakness, headaches, and even brain fog. But it also helps reduce hunger pangs and cravings associated with carb restriction.
Ketones are produced during the first stage of ketosis. These are molecules formed from excess acetyl groups on fats and proteins. They have a distinctive chemical smell.
Ketones are produced naturally by the human body. For example, they may be present in urine after fasting. Ketones are also produced when someone consumes a very low-calorie diet, such as a fast.
When people use the word “keto,” they usually mean the second type of ketosis — nutritional ketosis. This occurs when dietary carbohydrates are restricted to less than 50 grams per day, but protein intake remains relatively high at 1.0–1.5 g/kg of ideal body weight. In other words, a 150-pound man would eat about 75–100 grams of protein daily.
When ketones are present in the blood, the body enters the third stage of ketosis, known as therapeutic ketosis. It's important to note that these terms aren't precise because ketosis isn't a single condition; rather, it represents a series of conditions that occur over time.
Why Is It Called “Ketogenic”?
The word “keto” comes from the Greek word keton, meaning “acid.” When we say something is ketogenic, we mean it produces an acidic environment inside our bodies. This happens when we burn fat instead of carbohydrates for energy.
We produce ketones when we go into ketosis.
When we consume more carbohydrates than we use for fuel, the body converts them into glucose, which then gets converted into glycogen, a form of stored carbohydrate.
Glycogen stores are found in the liver and muscles.
During times of fasting or starvation, the body begins using its glycogen stores first before turning to fats.
That's why people who follow the ketogenic diet often feel hungry between meals.
They don't get enough food to fill up their stomachs because the body is burning through its glycogen stores.
If you're new to the ketogenic diet, you may not understand why you feel so hungry after eating.
But once you start feeling better, you'll see how easy it is to stay motivated by sticking to this way of eating.
How Does the Ketogenic Diet Work?
In order to enter ketosis, you need to consume fewer than 50 grams of carbs per day. That means limiting your consumption of bread, pasta, rice, potatoes, fruit, starchy vegetables, and sugary foods. Instead, focus on eating plenty of healthy fats like avocado, coconut oil, olive oil, nuts, seeds, butter, cheese, eggs, meat, fish, and bacon.
Carbohydrates provide four calories per gram, compared to only two calories per gram for protein and fat. Carbs also raise insulin levels, which slows down the release of fat from fat cells.
But once the body gets into ketosis, it burns fat instead of carbs for energy. And since most people who follow a ketogenic diet lose weight, it's clear why this approach works so well.
The ketogenic diet was developed more than 100 years ago, and it's still considered a safe way to control seizures in certain types of epilepsy. There's some evidence that suggests it might help with heart disease, too.
While this diet plan is quite restrictive, it does work. People who try it report losing up to 10 pounds in just one week.
What Is the Ketogenic Diet Like?
The ketogenic diet consists of lots of saturated fat, limited carbohydrate intake, and moderate amounts of protein.
It's similar to Atkins, except it doesn't require any specific food group restrictions. You can eat all sorts of foods, including dairy products, grains, fruits, and veggies.
You'll still want to limit refined sugar and processed foods, though.
It would be best if you aimed to keep your total calorie intake around 500 calories below the maintenance level (based on your age, gender, height, and activity).
The basic formula is 20% protein, 65% fat, 15% carbs.
This ratio will produce ketone bodies, which are used as an alternative fuel source by the brain.
If you stick to this macronutrient distribution, you won't get hungry.
Instead, you'll feel full and energized.
You'll have greater mental clarity, too.
Can I Lose Weight On The Ketogenic Diet?
Yes! Many people lose significant amounts of weight while following the ketogenic diet.
One study found that overweight adults lost 6 percent of their starting body weight after three months on the keto diet.
Another study followed children ages 9 to 12 for six months and found that those who were obese experienced the greatest weight loss.
How Long Will I Stay In Ketosis?
Ketosis is typically achieved within 2-3 days, but it may take longer depending on how much carbohydrate you consumed before starting the diet.
Once you reach ketosis, you're likely to stay there for about two weeks. After that, you'll start burning stored fat for energy, and you'll be able to return to normal carb intake.
How Do I Know If I Am In Ketosis?
To check whether you're in ketosis, use urine strips. These test strip kits measure ketones in your pee.
However, urine strips aren't perfect because they don't always detect ketones accurately.
That said, many people find them helpful in tracking progress.
There are other ways to track ketones in your blood, but these tests are expensive and not covered by insurance.
For now, using urine strips is the best option.
When To Start Eating Carbs Again?
After you reach ketosis, your goal is to reintroduce carbohydrates slowly into your diet.
Start with small portions at first, then gradually increase your carb intake over time.
When Should I Expect Results?
People who follow the ketogenic diet experience rapid results.
Some studies show that participants lose 3-4 pounds in the first week alone.
Other studies suggest that most people see improvements in cholesterol levels and blood pressure within four weeks.
However, it takes up to 90 days to fully adapt to the ketogenic diet. You may need to adjust your daily caloric intake during this adaptation period.
If you decide to try the ketogenic diet, make sure you monitor your blood glucose levels closely during your transition period.
Your doctor might also recommend taking a multivitamin supplement to ensure you're getting enough vitamins and minerals.
How To Start a Keto Diet?
There are two different types of diets that fall under the umbrella term “ketogenic.” One type focuses on restricting carbohydrates, while the other encourages a higher intake of healthy fats.
Both have been shown to help reduce hunger, improve mood, and promote weight loss.
However, there are pros and cons to each approach.
Let's take a closer look at both.
One of the most common ways to achieve ketosis is to restrict carbohydrates.
By limiting the number of carbs you eat, you force your body to begin producing ketones.
This process takes time, though, since the body needs about three days to adapt to this change in feeding habits.
Once you reach ketosis, however, you'll experience some benefits almost immediately.
For starters, you won't feel nearly as hungry during the day as you would with a standard Western diet.
You'll also find yourself craving healthier foods like meat, fish, and veggies.
On top of that, studies show that following a ketogenic diet can lead to significant improvements in blood pressure, cholesterol levels, and even brain function.
It's important to note that carb restriction isn't always necessary to enter ketosis.
Some people can simply cut back on their daily calorie intake without cutting out any carbs.
Still, it's best to avoid this approach if possible.
High Fat Intake
Another popular option for achieving ketosis is to increase the number of healthy fats you eat.
This means replacing processed carbs and sugars with real foods like avocado, eggs, full-fat dairy products, and nuts.
In addition to being rich in nutrients, fatty foods tend to keep us fuller longer than sugary ones.
So, if you want to lose weight, you might be tempted to skip breakfast altogether.
But doing so could actually make you hungrier later on.
A study published in Appetite found that skipping breakfast leads to increased appetite and cravings throughout the day.
Plus, research shows that eating a balanced meal early in the morning helps prevent overeating later in the day.
A Balanced Approach
As you can see, there are many options when it comes to achieving ketosis.
And while one approach works well for some people, others prefer another.
Ultimately, the goal should be to find an eating plan that feels right for you.
To do this, you need to figure out which approach works best for you based on your lifestyle and health goals.
Perform These Checklists Before Starting
Here are some questions to ask yourself before starting a ketogenic diet:
What Are Your Goals?
Before beginning a ketogenic diet, knowing exactly what you hope to get from it is essential.
Are you looking to lose weight? Or maybe you just want to improve your health.
Do you have certain medical conditions that require you to follow a specific diet?
How Much Weight Do You Want To Lose?
Some people choose to start a ketogenic diet simply to shed a few pounds.
However, most experts recommend that you set realistic goals.
For example, if you weigh 300 lbs, losing 20 lbs will not do anything but leave you frustrated.
Instead, aim for 5-10 lbs per month.
You can also track your progress with a scale.
Start With Small Changes
Many beginners find themselves overwhelmed by the amount of information available about the ketogenic diet.
It's okay to take baby steps when you begin.
Try following a modified version of the ketogenic diet for 2 weeks.
Then try another modification for 2 weeks.
After each change, keep track of your results.
Once you've mastered one type of diet, move on to another.
Don't Be Afraid Of Fat
Most people think of fats as bad for us.
But there are actually two types of fats: saturated and unsaturated.
Saturated fats tend to raise cholesterol levels in the blood.
Unsaturated fats lower cholesterol.
Saturated fats come from animal products such as meat, dairy, and eggs.
Unsaturated fatty acids come from plant sources such as nuts, seeds, avocados, olives, and olive oil.
Both types of fats are essential to human nutrition.
In fact, many studies show that diets rich in unsaturated fats help reduce heart disease risk factors like high blood pressure and diabetes.
So while you won't be able to eat butter and bacon forever, you should still include plenty of healthy fats in your diet.
Fats aren't all bad either.
Fatty foods contain lots of calories, but they also provide vitamins and minerals that our bodies need.
Fatty fish like salmon and mackerel are great examples of these nutrient-rich foods.
Eating fat doesn't mean you'll gain weight.
Studies show that people who eat a higher percentage of total calories from fat tend to maintain a healthier weight than those who consume more carbohydrates.
This makes sense since fat contains 9 calories per gram compared to 4 calories per gram for carbs.
While it's true that too much fat will increase your cholesterol level, it's possible to eat enough fat without worrying about your cholesterol.
That said, it's always best to talk to your doctor before changing your diet.
They can tell you whether you need to make any changes based on your current medications.
If you decide to go ahead with the ketogenic diet, here are some tips to keep in mind:
Eat Plenty of Protein
Protein helps build muscle tissue and repair cells.
When you lose weight, protein synthesis slows down.
A ketogenic diet keeps this process working at full speed, so you stay leaner longer.
Eat three to four servings of meat, poultry, seafood, eggs, cheese, milk, yogurt, beans, peas, and other nonstarchy vegetables every day to get enough protein.
Limit Your Carb Intake
Carbohydrates are made up of sugar molecules called glucose.
Glucose provides energy for your body.
Your brain uses almost exclusively glucose as fuel.
Your liver converts most dietary carbohydrates into glucose.
The rest gets stored as glycogen (a form of stored glucose) in your muscles and liver.
As long as your liver stores excess glucose, you don't have an issue.
However, when your liver starts converting extra glucose into fat, you start storing fat instead of burning it off.
This is why cutting back on carbs is important.
You want to limit your intake to 20 grams of net carbs a day.
Net carbs refer to the number of carbs remaining after subtracting fiber from total carb content.
You can calculate net carbs by adding up how many grams of carbs are found in fruits, veggies, legumes, and starchy veggies, then subtracting the grams of fiber.
For example, one cup of broccoli florets has 5 grams of carbs and 2 grams of fiber.
One serving of cooked brown rice has 12 grams of carbs and 1 gram of fiber.
One slice of bread has 8 grams of carbs and 3 grams of fiber.
Total carbs 5 + 12 + 8 + 3 26 grams
Subtract fiber 26 – 7 equals 19 grams of net carbs
19 grams divided by 30 equals 0.65 ounces of net carbs per day
That means you can eat about 65 grams of carbs per day.
Some people choose to count fiber separately.
In that case, you would add up the grams of carbs from fruits, veggies, legumes, and starches, then subtract the grams of fiber. This way, you can eat more carbs.
For example, a cup of raw broccoli has 6 grams of carbs and 2.5 grams of fiber.
A half-cup of cooked brown rice has 11 grams of carbs and 2 g of fiber.
A slice of whole-wheat toast has 10 grams of carbs and 3 g of fiber.
Total carb 6 + 11 + 10 + 3 equals 27 grams.
Subtract fiber 27 – 7 equals 20 grams of net carbs.
20 grams divided by 30 equals 0.67 ounces of net carbs per day.
So you could eat about 67 grams of carbs per day if you counted fiber separately.
We recommend counting carbs without fiber because it makes it easier to track your progress and stick to your plan.
Choose Healthy Fat Sources
Fat is essential for your health.
It helps protect your heart, reduces inflammation, and promotes satiety.
But too much fat will make you gain weight.
There are two types of fats: saturated and unsaturated.
Saturated fats come mainly from animal products like beef, pork, lamb, chicken, and dairy.
They raise cholesterol levels and increase your risk of cardiovascular disease.
Unsaturated fats come primarily from plant sources such as olive oil, avocado, nuts, seeds, fish, and soybeans.
They lower cholesterol levels and reduce your risk of cardiovascular disease, diabetes, and stroke.
What Foods Are Best For Ketosis?
As mentioned above, the main focus of the ketogenic diet is eating foods that contain minimal carbs.
These foods include meats, eggs, butter, full-fat dairy products, avocado, olives, coconut oil, heavy cream, cheese, and oils such as olive, flaxseed, hemp seed, and sesame seed.
In addition, you should limit your consumption of fruits, vegetables, grains, legumes, starchy tubers, and refined sugars.
This includes things like bread, pasta, rice, corn, potatoes, beans, peas, oats, and wheat.
While these foods are okay to eat occasionally, they should be limited to less than 10% of your total calories per day.
Medical Supervision May be Necessary
Before beginning, talk to your doctor about any health conditions you have, including diabetes, heart disease, kidney problems, thyroid disorders, epilepsy, migraines, depression, anxiety, or cancer.
It's important to note that some medications can interact badly with the ketogenic diet. Be sure to tell your doctor about all the medicines you take, especially ones that affect your kidneys (such as NSAIDs) or pancreas (such as insulin).
Also, let your doctor know if you've recently started or stopped taking supplements like vitamin D, calcium, iron, zinc, magnesium, omega fatty acids, probiotics, fish oil, or fiber.
It would be best to discuss any changes you plan to make to your exercise routine with your doctor.
You might want to avoid exercising excessively while following the ketogenic diet.
Excessive sweating can cause you to lose too much water and electrolytes, putting you at risk for dehydration.
Dehydration can lead to headaches, dizziness, fatigue, muscle cramps, and even seizures.
If you want to lose weight with a keto diet, you should avoid processed foods and focus on eating plenty of vegetables and healthy fats.
When you do this, you'll feel full and satisfied between meals.
You won't be hungry all day long.
And you'll enjoy better energy levels and fewer cravings.
It doesn't matter whether you follow the ketogenic diet strictly or not.
What matters most is sticking with it consistently over time.
Remember, losing weight isn't just about following a particular diet.
It's also about making lifestyle changes that support your goals.
I have been a nutritionist for the past ten years, and have faced many people who are almost desperate to get the ideal body shape. Don't let others judge you based on your appearance. Every effort you make will take you to a better stage of life. Research, do, analyze, and repeat the success that occurs.