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.
Ketogenic diets can cause massive reductions in blood sugar and insulin levels. This, along with the increased ketones, has numerous health benefits.
What “Keto” Means?
The “keto” in a ketogenic diet comes from the fact that it allows the body to produce small fuel molecules called “ketones”.
Ketosis is a normal metabolic process. When the body does not have enough glucose for energy, it burns stored fats instead; this results in a build-up of acids called ketones within the body.
Ketones are produced if you eat very few carbs (that are quickly broken down into blood sugar) and only moderate amounts of protein (excess protein can also be converted to blood sugar).
The liver produces ketones from fat. These ketones then serve as a fuel source throughout the body, especially for the brain.
The brain is a hungry organ that consumes lots of energy every day, and it can’t run on fat directly. It can only run on glucose… or ketones.
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 are also other less obvious benefits, such as less hunger and a steady supply of energy. This may help keep you alert and focused.
When the body produces ketones, it enters a metabolic state called ketosis. The fastest way to get there is by fasting – not eating anything – but nobody can fast forever.
A keto diet, on the other hand, can be eaten indefinitely and also results in ketosis. It has many of the benefits of fasting – including weight loss – without having to fast.
Fast Facts on Ketosis
Ketosis occurs when the body does not have sufficient access to its primary fuel source, glucose.
Ketosis describes a condition where fat stores are broken down to produce energy, which also produces ketones, a type of acid.
As ketone levels rise, the acidity of the blood also increases, leading to ketoacidosis, a serious condition that can prove fatal.
People with type 1 diabetes are more likely to develop ketoacidosis, for which emergency medical treatment is required to avoid or treat diabetic coma.
Some people follow a ketogenic (low-carb) diet to try to lose weight by forcing the body to burn fat stores.
Different Types of Ketogenic Diets
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 75% fat, 20% protein and only 5% carbs.
- 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.
Health Benefits Of Keto Diet
Burns fat: You can drop a lot of weight — and quickly — on the keto diet. Ketones suppress ghrelin — your hunger hormone — and increase cholecystokinin (CCK), which makes you feel full.
Reduced appetite means it’s easier to go for longer periods without eating, which encourages your body to dip into its fat stores for energy.
Reduces inflammation: The keto diet is anti-inflammatory, and could protect you against major degenerative diseases such as Alzheimer’s and cancer.
Fuels and feeds your brain: Ketones provide an immediate hit of energy for your brain, and up to 70% of your brain’s energy needs when you limit carbs. Fat also feeds your brain and keeps it strong. Your brain is at least 60% fat, so it needs loads of good fats to keep it running. Essential fatty acids such as omega-3s help grow and develop the brain, while saturated fat keeps myelin — the layer of insulation around the brain — strong so your neurons can communicate with each other.
Increases energy: Ketosis helps the brain create more mitochondria, the power generators within your cells. More energy in your cells means more energy for you to get stuff done.
Lowers blood sugar: The keto diet may reverse and even cure diabetes. Keto stabilizes insulin levels and lowers blood sugar, to the point that many diabetics can come off their medication when switching to the diet.
Mental Focus: Many people use the ketogenic diet specifically for the increased mental performance.
Ketones are a great source of fuel for the brain. When you lower carb intake, you avoid big spikes in blood sugar. Together, this can result in improved focus and concentration. Studies show that an increased intake of fatty acids can have impacting benefits to our brain’s function.
Foods to Avoid In Keto Diet
Any food that is high in carbs should be limited.
Here is 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: These are highly processed and often high in carbs.
- Some condiments or sauces: These often contain sugar and unhealthy fat.
- Unhealthy fats: Limit your intake of processed vegetable oils, mayonnaise, etc.
- Alcohol: Due to their carb content, many alcoholic beverages can throw you out of ketosis.
- Sugar-free diet foods: These are often high in sugar alcohols, which can affect ketone levels in some cases. These foods also tend to be highly processed.
Foods to Eat In Keto Diet
You should base the majority of your meals around these foods:
- Meat: Red meat, steak, ham, sausage, bacon, chicken and turkey.
- Fatty fish: Such as salmon, trout, tuna and mackerel.
- Eggs: Look for pastured or omega-3 whole eggs.
- Butter and cream: Look for grass-fed when possible.
- Cheese: Unprocessed cheese (cheddar, goat, cream, blue or mozzarella).
- Nuts and seeds: Almonds, walnuts, flax seeds, pumpkin seeds, chia seeds, etc.
- Healthy oils: Primarily extra virgin olive oil, coconut oil and avocado oil.
- Avocados: Whole avocados or freshly made guacamole.
- Low-carb veggies: Most green veggies, tomatoes, onions, peppers, etc.
- Condiments: You can use salt, pepper and various healthy herbs and spices.
It is best to base your diet mostly on whole, single-ingredient foods. Here is a list of 44 healthy low-carb foods.
Sample Keto Meal Plan For 1 Week
To help get you started, here is a sample ketogenic diet meal plan for one week:
Breakfast: Bacon, eggs and tomatoes.
Lunch: Chicken salad with olive oil and feta cheese.
Dinner: Salmon with asparagus cooked in butter.
Breakfast: Egg, tomato, basil and goat cheese omelet.
Lunch: Almond milk, peanut butter, cocoa powder and stevia milkshake.
Dinner: Meatballs, cheddar cheese and vegetables.
Breakfast: A ketogenic milkshake (try this).
Lunch: Shrimp salad with olive oil and avocado.
Dinner: Pork chops with Parmesan cheese, broccoli and salad.
Breakfast: Omelet with avocado, salsa, peppers, onion and spices.
Lunch: A handful of nuts and celery sticks with guacamole and salsa.
Dinner: Chicken stuffed with pesto and cream cheese, along with vegetables.
Breakfast: Sugar-free yogurt with peanut butter, cocoa powder and stevia.
Lunch: Beef stir-fry cooked in coconut oil with vegetables.
Dinner: Bun-less burger with bacon, egg and cheese.
Breakfast: Ham and cheese omelet with vegetables.
Lunch: Ham and cheese slices with nuts.
Dinner: White fish, egg and spinach cooked in coconut oil.
Breakfast: Fried eggs with bacon and mushrooms.
Lunch: Burger with salsa, cheese and guacamole.
Dinner: Steak and eggs with a side salad.
Always try to rotate the vegetables and meat over the long term, as each type provides different nutrients and health benefits.
Types of Keto Diet
Standard keto diet: You eat very low carb (less than 50 grams of net carbs a day), all the time. Some keto followers eat as few as 20 grams per day. Here’s how to find your ideal carb intake.
Cyclical keto diet: You eat high fat, low carb (less than 50 grams of net carbs a day) five to six days of the week. On day seven, you up your carb intake to roughly 150 grams, during what’s called a carb refeed day. Carb cycling this way helps you avoid the negative effects some people experience when they restrict carbs long term, like thyroid issues, fatigue and dry eyes.
Targeted keto diet: You follow the standard keto diet, but eat extra carbs right before (30 minutes to an hour) a high-intensity workout. The glucose is meant to boost performance, although no scientific studies have linked low blood glucose to reduced weight-lifting performance.
Dirty keto diet: Dirty keto follows the same ratio of fats, proteins, and carbs as the regular keto diet but with a twist: it doesn’t matter where those macronutrients come from. So dinner could be a bunless Big Mac with a Diet Pepsi.
Is Keto Diet For Everyone?
A ketogenic diet can be great for people who are overweight, diabetic or 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.
And, as with any diet, it will only work if you are consistent and stick with it in the long term.
That being said, few things are as well proven in nutrition as the powerful health and weight loss benefits of a ketogenic diet.
How to Know if You’re in Ketosis?
1. Weight Loss
One of the most obvious, yet deceptive signs of ketosis is weight loss. You could be losing weight because of the diet or because of a number of different reasons.
However, if you’re being strict with your ketogenic diet then you can more than likely attribute this ketosis symptom to the diet.
You will start to see the weight drop off consistently when your body is in ketosis. Eventually, you’ll probably hit a plateau with the weight loss but that won’t happen for some time.
When you switch to a low carb intake you usually experience significant weight loss in the initial week. In the first 28 days, there have been accounts of people losing over 10 pounds of fat. Here is an example of how somebody lost 12 lbs in the first 28 days of Keto.
It’s important to note that this initial weight loss is more than likely not fat. It is that water weight that was being held by the fat cells in your body.
When the fat cells hold onto the water, they can’t flow through your body and be used as energy so instead, your body will continue to store them.
Once you’re able to get rid of that water weight the fat will start to fall off. Any weight loss you see at this point will be fat.
2. Loss of Appetite
Funny thing about cutting carbs from your diet, you start to lose your appetite. You just don’t get as hungry as you used to be.
Don’t get me wrong, you won’t lose your appetite altogether, but it will take hours and hours before you start to feel that hungry feeling. There won’t be any worry for a snack an hour after your lunch break.
When you are eating, you are more than likely not going to overeat. Overeating is a problem that many people face without realizing it. A keto diet causes your body to have a satiated feeling for a much longer time.
This is a big reason for not having as much of an appetite.
3. Increased Focus and Energy
This is something that I’m sure everyone can benefit from. Having increased focus and energy can lead to a lot more possibilities in almost all aspects of your life.
A lot of you, like me, are probably the type of person that may struggle to wake up in the morning or stay awake throughout the day without fighting the urge to take a nap. A keto diet can help you stay awake and alert for a much longer time during the day.
No more urges to take a nap.
This is a small difference that can lead to much better health results down the road.
When you’re producing ketones, your body is using this as energy. In ketosis, your body is producing even more ketones and this leads to even more energy. Having an excess amount of energy will allow your brain to almost function fully for a much longer time.
4. Short-Term Fatigue
Yes, I know, this completely contradicts the point I just made, but just hear me out for a second.
Starting a keto diet is a big change in lifestyle. Your brain is going to need time to adjust.
Everything about your body has to change. It’s not used to what you’re starting to put it through.
Your body is so used to having sugar that is all it’s looking for initially. When it doesn’t find any of that, you can say that there is some sort of lag time during this short adjustment period. This is when you feel that fatigue.
During the entirety of a keto diet, your body will be releasing a lot of electrolytes as well so you need to do what you can to keep them in your system, mostly by staying as hydrated as possible.
Staying hydrated and maintaining electrolytes will help your body combat the short-term fatigue you will probably have.
You can easily replenish your electrolytes through special drinks and supplements or through your food. Adding sodium (salt) to your food will help add more electrolytes to your diet.
5. Toilet Issues
By toilet issues, I mean bowel movements. As hard as that may be to accept, it’s not going to be what it once was.
Your body will react in one of three ways here:
- Constipation – You may go days without going to the bathroom. A simple solution may be to add a bit more fiber to your diet.
- Diarrhea – This definitely sounds horrible, but it could be something that goes with the saying, “Things get worse before they get better.”
- Nothing – The people that don’t experience any change can be considered the lucky ones as there bowel movements go on as normal.
6. Bad Breath
Some of us wake up with bad breath already. Imagine having bad breath even after brushing your teeth. Doesn’t mean anything is wrong with you.
This could just mean that your body is producing more acetone than normal. The only way acetone leaves your body is in your urine or through your breath. So expect your pee to smell a bit too.
Chewing gum or keeping mints nearby is adviced. You don’t want to run into the wrong person and have a conversation with them when you have horrible smelling breath.
Luckily, the bad breath won’t last forever. The longer you stick with the diet, the more normalized your breath will become.
7. Short-Term Decreases in Performance
This can tie into the short-term fatigue. Fatigue usually leads to drops in performances, but not always.
When you’re exercising at first, you’re probably going to feel as though you have less energy than you usually do.
Even if you’re already in shape, you could find some workouts to be harder because of your lack of energy.
This is just because your body is going through a lot of changes. Expect this to change in about a weeks time when your body has started to get used to the very little carbs it’s consuming.
8. Increased Ketones
When your body is in ketosis, you will have more ketones. That is a byproduct of being in ketosis.
In other words, lack of sleep. You can expect to wake up in the middle of the night and not get a full nights rest.
No need to worry, this will improve over a short period of time.
Again, your body is going through a lot of changes and needs a time period to adjust.
What Are The Risks of Keto Diet?
A ketogenic diet has numerous risks.
Top of the list: it’s high in saturated fat. McManus recommends that you keep saturated fats to no more than 7% of your daily calories because of the link to heart disease. And indeed, the keto diet is associated with an increase in “bad” LDL cholesterol, which is also linked to heart disease.
Other potential keto risks include these:
Nutrient deficiency. “If you’re not eating a wide variety of vegetables, fruits, and grains, you may be at risk for deficiencies in micronutrients, including selenium, magnesium, phosphorus, and vitamins B and C,” McManus says.
Liver problems. With so much fat to metabolize, the diet could make any existing liver conditions worse.
Kidney problems. The kidneys help metabolize protein, and McManus says the keto diet may overload them. (The current recommended intake for protein averages 46 grams per day for women, and 56 grams for men).
Constipation. The keto diet is low in fibrous foods like grains and legumes.
Fuzzy thinking and mood swings. “The brain needs sugar from healthy carbohydrates to function. Low-carb diets may cause confusion and irritability,” McManus says.
Those risks add up — so make sure that you talk to a doctor and a registered dietitian before ever attempting a ketogenic diet.
Is a Keto Diet Safe?
A keto diet is usually very safe.
The truth is that we can’t say for certain that it is 100% safe. Humans don’t understand everything under the branch of nutritional science and probably won’t for a very long time. As an individual, the only thing you can do is take a look at the research yourself and form your own conclusion.
How Long Does It Take to Be In Ketosis?
It varies, from a day or two, up to a week or more. People with more insulin resistance (e.g. people with type 2 diabetes) usually take longer, while young and lean people generally get into ketosis far more quickly.
Can I Eat a Keto Diet as A Vegetarian or Vegan?
A keto diet can work for many non-meat-eaters, depending on what other types of food their diets include.
A lacto-ovo vegetarian eats dairy and eggs, whereas a lacto-vegetarian eats dairy but doesn’t eat eggs. There is also a subset of vegetarians known as pescatarians who include fish in their diet but avoid poultry and other meat.
Although following keto as a vegetarian is definitely doable, it can be a little challenging, especially when first starting out.
Is Keto Safe During Pregnancy?
A keto diet appears to be safe during pregnancy, judging from the experiences of people who have done it and doctors used to treating patients using a keto diet during pregnancy. It may also be very helpful in case of gestational diabetes.
Getting Started With Keto Diet
So how do you get started with keto diet?
- Understand meal planning and plan your meals so you don’t have missteps
- Calculate your daily macro goals
- Drink enough water
- Get enough sleep
When getting started on the keto diet you don’t want your daily macros to exceed 20g of carbs. You want to cut out all sugar and have most of your carbs come from vegetables.
The reality of it is, if you want to get started you can dive right in after you’ve caclulated your macros and planned some meals.
If you aren’t in the mood to plan meals right now then you can just go off of what your body tells you and eat what when you feel hungry although this usually means you fall short of your macro goals.
It’s important that you make food that you enjoy. Being on keto isn’t about missing out on food you love. It’s about finding the food you love that is great for your body.