The ketogenic diet is rapidly growing in popularity as a weight-loss and wellness diet. Google searches for this diet are skyrocketing , and we're seeing a growing number of new keto supplements on the market. But what is keto diet exactly and how does it work?
The keto diet is definitely not a new trend or passing fad; the diet has been around for decades — since the 1920s to be more exact. And many of the principles behind this diet are even older, dating back to 500 BC . It's only recently that people are rediscovering this diet for weight loss and better health.
If you've heard about this diet from friends, wellness blogs, and celebrities and would like to learn more, then do keep reading. In this overview, we explain everything you need to know about this diet to clear any confusion you might be having.
The ketogenic (ketone-generating) diet is a very -low-carb diet (VLCD). Other than being low in carbs, the diet is exceptionally high in fat: 65 to 80% of calories come from fat when you go keto. The higher fat intake combined with reduced carb intake produces ketones – three acidic molecules that replace glucose in your body.
The three ketones your body makes on a keto diet are:
- Acetoacetate– A simple ketone and the first ketone produced. Your heart and kidneys prefer using over glucose as fuel. Your brain, on the other hand, uses acetoacetate only when glucose levels are low.
- Beta-hydroxybutyrate (BHB) – Your body makes BHB from acetoacetate. Your brain uses BHB when blood glucose levels are low.
- Acetone – Acetone is the simplest and smallest of the three ketone bodies. It is a byproduct of the other two ketone bodies. However, it is not a waste product as studies show that acetone balances out pH and provides fuel to peripheral tissue .
These ketones take the place of glucose in your body to provide energy when you restrict carbs. Normally, your body runs on glucose which is a simple sugar broken down from carbs. Glucose enters cells where mitochondria turn it into adenosine triphosphate (ATP) – the molecular unit of currency of cell energy.
But in the absence of glucose, your body starts releasing fatty acids from fat stores to be used as energy. Because the brain and liver cannot use fats directly for energy and instead, rely on ketones. The reason your brain can't use fats for energy is because most fats cannot cross the blood-brain barrier.
History of the Ketogenic Diet
Back in the 5th century BC, Hippocrates observed that fasting reduced seizure frequency. Ever since that time, doctors were prescribing fasting to treat epilepsy and other disorders that cause seizures. However, nobody really understood the mechanism behind this until the beginning of the 20th century.
In the early 1920s, scientists made two pivotal discoveries , namely that starvation boosts ketone levels and that a low-carb, high-fat diet does the same. Dr. Wilder at the Mayo Clinic was the first researcher to propose such a diet to children with epilepsy and he called it "ketogenic diet."
Later on, Dr. Peterman designed the macronutrient ratios for the ketogenic diet which are still in use today: 1 g of protein per kilogram of body weight (for kids), 10–15 g of carbs per day, and a liberal intake of fat. However, on most keto website, you'll see these macronutrient ratios for the keto diet:
- 60-75% of calories from fat
- 15-30% of calories from protein
- 5-10% of calories from carbs
These macros are the cornerstone of the keto diet, so make sure to remember them if you plan to go keto. But they're not set in stone though. A bit of tweaking is necessary, so the keto diet can match your age, sex, body composition, activity levels, and health. That's why keto proponents designed different versions of the diet:
Targeted Ketogenic Diet (TKD)
For highly active ketoers, the TKD involves eating carbs around workouts. These carbs are still kept low to around 30-50 grams per day, so it's all about the timing. The TKD gives you more energy during workouts as muscles may struggle to use ketones and fatty acids for energy.
Cyclic Ketogenic Diet (CKD)
This keto diet version is for advanced athletes like endurance runners and powerlifters. The diet involves eating a high amount of carbs two to three days before a competition to replenish glycogen stores. Sometimes, athletes will eat over 120 grams of carbs a day. The diet is often referred to as carb cycling.
Restricted Ketogenic Diet (RKD)
This keto version restricts carbs often below 20 grams per day. The diet also often involves water fasting for a couple of days followed by low-carb and low-calorie eating. The goal is to cause a drastic drop in blood glucose and boost blood ketone levels to 4.0 mM. The diet is effective in fighting cancer because it starves cancer cells of its primary fuel source – glucose .
The ketogenic diet comes with far-reaching benefits. Researchers are just beginning to unravel many of these benefits, and so far, we know that keto helps with the following:
The keto diet is your ultimate fat-burning diet. Without enough carbs to fuel your brain, your body has no other option than to burn its own fat stores. Normally, your body is reluctant to burn fat and will only do so in case of emergencies. The keto diet creates this emergency through carb deprivation.
But what's best about all this is that keto will not leave you malnourished, hungry, tired, and in ill health. That's because you eat lots of protein and fat-rich foods and because ketosis has a natural appetite suppressing effect .
A diet that makes you lose weight while increasing your energy? This well-known effect of keto is the result of increased ketone levels which happen to be a powerful fuel source. Studies show that BHB provides more energy per unit oxygen used .
Besides that, your blood insulin levels stabilize on a keto diet, leaving your with fewer energy surges and slumps. Instead, what you get is a steady flow of energy from ketones. You'll feel this as greater mental and physical energy and may even have trouble sleeping in the first weeks as a result of this.
A big part of controlling diabetes involves keeping blood glucose at normal levels . The ketogenic diet, being a low-carb diet, definitely helps with this. A study involving 21 type II diabetics found that keto improved blood sugar levels so much that most participants either discontinued or reduced their medication .
The same study also notes that because keto is so effective in lowering blood glucose levels, those on diabetes medication should adjust their medication to avoid hypoglycemia. Studies also show keto is effective for type I diabetes and that it reverses diabetic kidney disease .
We already mentioned how keto starves cancer cells of glucose, thus inhibiting its spread. Well, researchers are now seriously considering this diet as an adjuvant cancer therapy . Researchers state the diet works to fight cancer also also by reducing levels of insulin and insulin-like growth factor – important drivers of cancer cell proliferation.
The best versions of keto to fight cancer are those including up to 25% medium-chain triglycerides and 75% long-chain triglycerides. Calorie restriction is also important for increasing the effectiveness of keto against cancer. Most studies to date confirmed keto was effective against brain cancer, colon cancer, pancreatic cancer, lung cancer, and breast cancer.
Keto boosts all aspects of brain health, so it's no wonder it's an effective therapy for a wide range of condition. From epilepsy control and migraine reduction to slowing down Alzheimer's and mitigating depression, keto does wonders for the brain. But how does it actually work?
Well, studies show that ketones can satisfy 70% of your brain's energy needs and that they're more effective at this than glucose . Because ketones don't need much oxygen to fuel brain cells, they reduce oxidative stress in the brain. Ketones also increase mitochondrial efficiency and increases neuron survival.
Cardiovascular diseases include atherosclerosis, coronary heart disease, and heart attack. For decades, doctors have been telling the public to cut back on fat, especially saturated fat to reduce the risk of these diseases. This recommendation came after studies linked fat intake with high cholesterol and high cholesterol with arterial plaque.
However, newer studies show that refined sugar is the bigger offender here and that the link between fat intake and raised cholesterol is poor . With that out of the way, keto despite being a high-fat diet will not lead to cardiovascular problems. In fact, studies show that the diet improves biomarkers for cardiovascular health .
How the Keto Diet Looks Like
Now that you know the theory, history, and benefits of keto, you're probably curious how this diet looks in practice. High-fat, low-carb are broad terms and can mean anything. To make the keto diet as healthful as can be and to boost its nutrient profile, keto experts rely on the following food staples to make up keto meals:
The healthiest oil on the planet is also a keto favorite. Rich in heart-healthy monounsaturated fatty acids and abundant in antioxidants, this oil is bound to keep you in prime on the diet.
Avocado is a true keto gem of a fruit. It's high in fat (15%) and low in carbs (2%). The mighty avocado is rich in fiber which is hard to get on a keto diet. This fruit also provides a handful of micronutrients such as vitamins C, E, K, folate, and potassium.
Butter not only makes everything taste good, but it helps you reach your keto macros. Don't fret the saturated fats in butter as they have a place in healthy diets according to new studies .
Pork belly, chicken thighs, ground beef, and even fatty fish are all good on keto. These provide moderate amounts of protein in addition to fat.
As long as it's not milk or skimmed, you can add it to your keto diet. Cheese, cream, yogurt, and even buttermilk are fine. Eggs are also an excellent source of protein and omega-3 fatty acids.
Fruits and vegetables have their place in a keto diet as long as they contain less than 10 grams of carbs per serving. To learn which fruits and vegetables are best for ketosis, read our article here.
Most nuts and seeds are low in carbs and high in fat. There are a couple of exceptions, though. Cashews and chestnuts are higher in carbs than other nuts, so avoid these at all costs.
Besides these ingredients to make up the base of your keto diet, you can also include nuts milks (almond and coconut), nut flours, non-nutritive sweeteners (stevia and erythritol), tofu, herbs, spices, and algae.
Your keto meals should be balanced to meet your daily macros and needs for fiber, minerals, and vitamins. There are countless keto recipes to help you with just that. Our Recipes section contains over 300 keto-approved recipes with nutrition facts included.
Considering Keto Supplements
The ketogenic diet works well without supplements. However, adding supplements to your keto diet can make things a bit easier. Here is how each supplements helps you on your keto journey:
MCT stands for medium-chain triglycerides, which are types of saturated fat found in coconut and palm kernel oil. MCT oil is a pure and concentrated source of these fats. Studies on MCT show it causes greater fat loss than any other fat .
However, what makes MCT oil particularly interesting for keto is the way it is digested. Unlike other fats, MCTs don’t require enzymes or bile for digestion. Instead, they get absorbed in the first part of the small intestines from where they reach the liver. In the liver, MCTs are used for immediate energy and ketone production and rarely does your body store them.
Exogenous ketones are ketones made in the laboratory and sold as supplements. They have the same chemical structure as the ketones your body makes. Dieters use exogenous ketones to correct mistakes, get into ketosis faster, or treat the keto flu.
When you take exogenous ketones, your blood ketone levels will be elevated for at least 8 hours . There are several benefits to this. First, having elevated levels of ketones suppress appetite. Secondly, exogenous ketones provide immediate energy for better workouts. And lastly, they help boost mental focus, especially when taken in the morning.
Collagen peptides are the hydrolyzed collagen, which is the most abundant protein in your body. Your body normally makes collagen on its own from amino acids. But taking collagen peptides also helps increase levels of this important protein in your body for stronger bones, muscles, and younger skin.
Keto dieters also take collagen peptides because they’re easy on the digestive tract. You’re probably familiar with how protein supplements can irritate the stomach and intestine. This is definitely not the case with collagen which actually improves intestinal barrier functioning according to some studies .
The keto diet is generally safe for most people. This is especially true when you follow the diet correctly, take enough fluids, and periodically have your health checked. But if you don’t take all the necessary steps to stay healthy on keto, things can go wrong. Here are a few words of precaution to help you avoid keto mishaps:
Not Being in Ketosis
If you are following the keto diet by eating lots of fat without being in ketosis, you are setting yourself up for failure. But not only that, chances are you’ll gain weight and jeopardize your health. Entering ketosis is crucial for the keto diet to work.
To check if you’re actually in ketosis, try out these Ketone Urine Test Strips. Alternatively, you can check for signs of ketosis to find out. To make sure you’re on your way towards ketosis, monitor your carb intake and make sure the food you’re eating does not contain hidden carbs.
Not Replenish Electrolytes
Losing electrolytes is nothing unusual in the first few weeks on the keto diet. However, it can become problematic if not addressed. Many keto dieters make sure they’re drinking eight glasses of water a day and supplementing with electrolytes.
Electrolyte imbalances can lead to dangerous dehydration and heart arrhythmias. They can also leave you feeling weak, irritable, and tired. Replenish your electrolytes daily by adding salt, bouillon cubes, or leafy greens to your fluids.
Not eating enough fat
Fat is your friend on keto. As long as you’re keeping your carb intake to below 50 grams per day, you won’t have to worry about fat making you fat. Instead, the fat you eat on a keto diet helps boost ketone production; increase your intake of essential fatty acids and fat-soluble vitamins, and provides you with immediate energy.
To ensure you’re eating enough fat, make a weekly meal plan with all the macros included. Also, it’s a good idea to include a variety of healthful fats like monounsaturated fatty acids, essential omega-3 fatty acids, and lauric acid from coconut oil.
And as far as contraindications go, there are lists of rare conditions that make keto dieting dangerous. These are mostly inborn errors of fat metabolisms and include :
Besides the conditions above, anyone with the following should be careful about following keto:
The ketogenic diet has been around for quite some time. However, it’s only recently that this low-carb, high-fat diet is getting attention from wellness enthusiasts, celebrities, and anyone wanting to improve their health.
The diet takes a unique approach to nutrition with the intent of completely transforming your metabolism. On keto, you make the shift from being a sugar burner to a fat burner. And best of all, you don’t feel tired and hungry along the way.
Learning as much as you can about keto will help you understand how this diet works and remove any doubt you might have about its safety and efficiency.
Ready to try out keto for yourself, take the tips listed here and go shopping for keto staples today. You’ll see that reaching ketosis is as easy as can get and, most importantly, that keto works.