Common Questions About the Ketogenic Diet
1. What Is the Ketogenic Diet?
The Ketogenic diet is a very low-carb diet plan that was originally designed in the 1920s for patients with epilepsy by researchers working at Johns Hopkins Medical Center. Researchers found that fasting — avoiding consumption of all foods for a brief period of time, including those that provide carbohydrates — helped reduce the amount of seizures patients suffered, in addition to having other positive effects on body fat, blood sugar, cholesterol and hunger levels. (4)
Unfortunately, long-term fasting is not a feasible option for more than a few days, therefore the ketogenic diet was developed to mimic the same beneficial effects of fasting. Essentially the keto diet works by “tricking” the body into thinking it is fasting, through a strict elimination of glucose that is found in carbohydrate foods. Today the ketogenic diet goes by several different names, including the “no-carb diet” or “very low carbohydrate ketogenic diet”(LCKD or VLCKD for short).
What does “keto” stand for exactly? Keto is short for ketosis. Following a ketogenic diet puts your body into a state of “ketosis,” which is a metabolic state that occurs when most of the body’s energy comes from ketone bodies in the blood, rather than from glucose. This is in contrast to a glycolytic state, where blood glucose (sugar) provides most of the body’s fuel (or energy).
Once ketone levels in the blood rise to a certain point, you officially enter into a state of ketosis. This state results in fairly rapid and consistent weight loss until you reach a healthier (and stable) body weight. Overall, people enter into ketosis at different rates, usually after 3–4 days of fasting or following a very low-carbohydrate diet (20 grams of net carbs or less) that forces the need for an alternative energy source.
When you’re following a ketogenic diet, your body is burning fat for energy rather than carbohydrates, so in the process most people lose excess body fat rapidly, even when consuming lots of fat and adequate calories through their diet.
2. What Are the Stages of Ketosis?
Ketosis occurs when the liver breaks down fat into fatty acids and glycerol — a process called beta-oxidation. In particular, three primary types of ketone bodies that are water-soluble molecules are produced: acetoacetate, beta-hydroxybutyrate and acetone.
Rather than drawing energy from glucose, a person in ketosis stays fueled off of these circulating ketones or ketone bodies — essentially, burning fat for fuel. This is the principal goal of the ketogenic diet, which can be achieved by adhering to a very low-carbohydrate, high-fat diet with only moderate amounts of protein.
3. What Is a Ketogenic Diet Plan Like?
Wondering how many carb foods you can eat and still be “in ketosis”? The traditional ketogenic diet created for those with epilepsy consisted of getting about 75 percent of calories from sources of fat (such as oils or fattier cuts of meat), 5 percent from carbohydrates and 20 percent from protein. For most people a less strict ketogenic diet (what I call a “modified keto diet”) can still help promote weight loss in a safe, and often very fast, way.
Reducing calories coming from carbohydrates to just 5 percent may not be appropriate or many people, but this shouldn’t mean that the keto diet is completely ruled out (more on following a modified keto diet can be found below).
Keep in mind that if a strict ketogenic diet is being followed, experts recommend that children following the diet be closely monitored, in addition to those who have who are taking medications or existing conditions like high blood pressure or diabetes.
For adults who are relatively healthy, it’s usually safe to follow a very low carb diet while not being monitored as closely, as long as they’re watching out for any unusual warning signs of a negative reaction (such as lots of fatigue or brain fog that lasts for more than about a week).
In some ways, it’s similar to the Atkins Diet, which similarly boosts the body’s fat-burning abilities through eating only low-carb foods, along with getting rid of foods high in carbs and sugar. Removing glucose from carbohydrate foods will cause the body to burn fat for energy instead. The major differences between the classic keto diet and the Atkins diet is ketogenic emphasizes healthier fats, less overall protein and no processed meat (such as bacon) while having more research to back up its efficacy.
4. How Does the Ketogenic Diet Work?
Ketogenic diets, like most low carb diets, work through the elimination of glucose. Because most folks live on a high carb diet, our bodies normally run on glucose (or sugar) for energy. We cannot make glucose and only have about 24 hours’ worth stored in our muscle tissue and liver. Once glucose is no longer available from food sources, we begin to burn stored fat instead, or fat from our diets. The ketogenic diet, therefore, eliminates glucose and causes the body to burn its own fat quickly.
This process of burning fat provides more benefits than simply helping us to shed extra weight — it also helps control the release of hormones like insulin, which plays a role in development of diabetes and other health problems. When we eat carbohydrates, insulin is released as a reaction to elevated blood glucose (an increase in sugar circulating in our blood). Insulin is a “storage hormone” that signals cells to store as much available energy as possible, initially as glycogen (aka stored carbohydrates in our muscles) and then as body fat.
The ketogenic diet works by eliminating carbohydrates from the diet and keeping the body’s carbohydrate stores almost empty, therefore preventing too much insulin from being released following food consumption. This can help reverse “insulin resistance” which is the underlying problem contributing to diabetes. Optimal ketosis is reached when they body stays in ketosis for at least a few weeks, when both any side effects diminish greatly while the benbsefits are more pronounced with the body becoming a fat burner.