In this article we will discuss what exactly is a ketogenic diet. This is going to be an educational objective introductory article explaining what a ketogenic diet is, how ketosis works, how it’s different from other diets, and to whom it might apply.
What is keto? Simply put, a ketogenic diet is a diet that’s low in carbohydrates, moderate in protein, and high in dietary fat. Originally in the 1920s, the ketogenic diet was designed for patients with epilepsy, to help reduce their seizures. The keto diet also tended to have positive effects on those patients’ body fat, blood sugar, cholesterol, and hunger levels. It has not been studied widely in terms of nutritional science though.
To understand the keto diet, we’ve got to start from the beginning – calories and macros. Calories are energy, it’s important to recognize that weight gain and weight loss are complicated. Calories in and calories out is too simple and not accurate enough. Exercise is important for a healthy lifestyle, but it has minimal impact in terms of weight loss, while it does of course provide other health benefits.
Burning 300 calories in a workout doesn’t equate to burning off a cupcake. Nutrition is going to be about 90% responsible for changes in our bodies in terms of weight. Different types of foods metabolize differently in the body. There are many variables, that’s why eating 2000 calories of fruit is not the same thing as eating 2000 calories of goldfish.
Macronutrients consist of protein, carbohydrates and fat. All calories come from these sources (with alcohols the exception). Your total calories for the day, no matter how many you eat and what diet you follow, equal 100%. Each of those micronutrients becomes a percentage of their daily pot, and the ratio will often change based on the diet.
You cannot have 100% of calories come from each macronutrient, that would be 300%, and because math exists, that just isn’t possible. You can have an equal number of calories from each food – 33.3%, but that contains more calories per gram than protein or carbs, so the percentage would be different. In that case, a popular diet you may have heard of, is a high-carb, low-fat diet for 80 /10/ 10. That means 80% of calories come from carbs, 10% from fat, and 10% from protein.
Competitive bodybuilders often build muscle with a diet that’s higher in carbs and lower in fat, with moderate protein. And then closer to their competition, when they need to lean out, protein becomes the biggest macronutrient in their diet, followed by fat and carbs. A ketogenic diet, on the other hand, consists of a diet that is around 70% fat, a moderate amount of protein, and very little carbs- only 5 to 10%, depending on the person’s tolerance.
Now it’s not a strict ratio, because it will vary from person to person. We all have a different carbohydrate tolerance and our insulin resistance levels are different, which means one person on a keto diet may be able to eat more carbs than another person on a keto diet, but still be in nutritional ketosis.
We realize that this may sound very different from what most of us have been taught about nutrition. We had always been taught that you don’t want to eat a lot of fat, but a keto diet functions differently than some other common diets, such as a diet higher in carbs with less fat and protein, that we are typically told is healthy. It’s important to recognize from the beginning that there is no right or wrong ratio, but there may be one that works better for you and only you can find that out.
So we know that calories are fuel for our bodies, but that fuel can come from one of two main sources- glucose or ketones. The main one that most people function off of today is glucose. It can be a great energy source for the brain and body and comes primarily from carbohydrates. This is essentially a sugar burning mode, since glucose is a sugar. The second source of fuel is ketones or ketone bodies. People on a ketogenic diet are fueled by ketones rather than glucose. Ketones are produced when glucose levels fall and the body has access to fat either in the form of stored body fat or dietary fat.
When someone’s body uses ketones as fuel rather than glucose, they are in nutritional ketosis, which is like a fat burning mode, since fat is the fuel source. For any diet, it’s important to have both carbohydrates and fat for the body to function properly, however it’s the amount of one relative to the other that will determine your fuel source. And one is not right or wrong.
Now if glucose is available to the body, it will use that first, because it’s easy to burn up. If you eat a lot of carbohydrates, your body will use that glucose as its fuel source, rather than using fats as fuel. This is why carbohydrate intake must be low on a ketogenic diet and a keto diet is often referred to as a high fat diet.
Dietary fat needs to be prevalent enough in the body in order to produce ketones. Many people associate the word fat with fat on our bodies and are unfamiliar with it as a fuel source. There’s a lot of misunderstanding about how a ketogenic diet works, which is why there’s also a lot of criticism surrounding it. Our brains and bodies do need some glucose, just like we all need some dietary fat, but glucose does not need to be the main source of energy for a body to function healthily.
Glucose is one energy source, ketones are another. Neither is right or wrong, they’re just different. In fact, our ancestors may have lived ketogenic lifestyles without being aware of them. As hunters and gatherers our ancestors ate lots of nuts, seeds, meats, and lower carb fruits like berries. This is often referred to as primal eating and it’s a diet that was high in fats and low in carbohydrates. It likely resulted in ketosis and helped our ancestors survive from one meal to the next, because their bodies could store that fat as energy.
There are still benefits to diets like these, that are lower in carbs and contain fats, but lower carb does not equal ketosis necessarily. Ketosis is a physical biological process that goes on in the body. It’s brought on when the fat to carb ratio is just right. High enough fat, low enough carb for that person’s body. If there isn’t enough fat or if there’s too much glucose or protein which we now know can be converted into glucose, the body will use the glucose instead and be in a state of glycolysis aka that sugar burning mode.
We’ve established that a keto diet exists, but why would someone want to be in ketosis? Are there benefits of following a ketogenic diet? One of the benefits is weight loss, in ketosis the body is able to burn stored fat and insulin levels are lowered, since there is less glucose in the body.
Reduced appetite, since fat is more satiating. People often don’t get as hungry on a ketogenic diet, which can improve a person’s relationship with food. You may also experience more mental clarity. People in ketosis often report experiencing a level of mental clarity they don’t have when fueled like glucose. Healing- studies have also shown it can help heal cancer cells and help to treat or even reverse cognitive impairments like Alzheimer’s symptoms. Improved insulin levels, reduced blood pressure and improved blood cholesterol and triglyceride levels, etc.