What is Ketogenic Diet?
The keto diet is a low carb, high fat diet. It lowers blood sugar and insulin levels and shifts the body’s metabolism away from carbs and toward fat and ketones.
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 significant reductions in blood sugar and insulin levels. This, along with the increased ketones, has some health benefits.
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 70% fat, 20% protein, and only 10% 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.
What is ketosis?
Ketosis is a metabolic state in which your body uses fat for fuel instead of carbs.
It occurs when you significantly reduce your consumption of carbohydrates, limiting your body’s supply of glucose (sugar), which is the main source of energy for the cells.
Following a ketogenic diet is the most effective way to enter ketosis. Generally, this involves limiting carb consumption to around 20 to 50 grams per day and filling up on fats, such as meat, fish, eggs, nuts, and healthy oils.
It’s also important to moderate your protein consumption. This is because protein can be converted into glucose if consumed in high amounts, which may slow your transition into ketosis.
Practicing intermittent fasting could also help you enter ketosis faster. There are many different forms of intermittent fasting, but the most common method involves limiting food intake to around 8 hours per day and fasting for the remaining 16 hours.
Blood, urine, and breath tests are available, which can help determine whether you’ve entered ketosis by measuring the amount of ketones produced by your body.
Certain symptoms may also indicate that you’ve entered ketosis, including increased thirst, dry mouth, frequent urination, and decreased hunger or appetite.
Ketogenic diets can help you lose weight
A ketogenic diet is an effective way to lose weight and lower risk factors for disease. In fact, research shows that the ketogenic diet may be as effective for weight loss as a low fat diet.
What’s more, the diet is so filling that you can lose weight without counting calories or tracking your food intake.
One review of 13 studies found that following a very low carb, ketogenic diet was slightly more effective for long-term weight loss than a low fat diet. People who followed the keto diet lost an average of 2 pounds (0.9 kg) more than the group that followed a low fat diet.
What’s more, it also led to reductions in diastolic blood pressure and triglyceride levels.
Another study in 34 older adults found that those who followed a ketogenic diet for 8 weeks lost nearly five times as much total body fat as those who followed a low fat diet.
The increased ketones, lower blood sugar levels, and improved insulin sensitivity may also play a key role.
Ketogenic diets for diabetes and prediabetes
Diabetes is characterized by changes in metabolism, high blood sugar, and impaired insulin function. The ketogenic diet can help you lose excess fat, which is closely linked to type 2 diabetes, prediabetes, and metabolic syndrome.
One older study found that the ketogenic diet improved insulin sensitivity by a whopping 75%.
A small study in women with type 2 diabetes also found that following a ketogenic diet for 90 days significantly reduced levels of hemoglobin A1C, which is a measure of long-term blood sugar management.
Another study in 349 people with type 2 diabetes found that those who followed a ketogenic diet lost an average of 26.2 pounds (11.9 kg) over a 2-year period. This is an important benefit when considering the link between weight and type 2 diabetes.
What’s more, they also experienced improved blood sugar management, and the use of certain blood sugar medications decreased among participants throughout the course of the study.
Other health benefits of keto
The ketogenic diet actually originated as a tool for treating neurological diseases such as epilepsy.
Studies have now shown that the diet can have benefits for a wide variety of different health conditions:
- Heart disease. The ketogenic diet can help improve risk factors like body fat, HDL (good) cholesterol levels, blood pressure, and blood sugar.
- Cancer. The diet is currently being explored as an additional treatment for cancer, because it may help slow tumor growth.
- Alzheimer’s disease. The keto diet may help reduce symptoms of Alzheimer’s disease and slow its progression.
- Epilepsy. Research has shown that the ketogenic diet can cause significant reductions in seizures in epileptic children.
- Parkinson’s disease. Although more research is needed, one study found that the diet helped improve symptoms of Parkinson’s disease.
- Polycystic ovary syndrome. The ketogenic diet can help reduce insulin levels, which may play a key role in polycystic ovary syndrome.
- Brain injuries. Some research suggests that the diet could improve outcomes of traumatic brain injuries.
However, keep in mind that research into many of these areas is far from conclusive.
Foods to avoid
Any food that’s high in carbs should be limited.
Here’s 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: low fat mayonnaise, salad dressings, and condiments
- some condiments or sauces: barbecue sauce, honey mustard, teriyaki sauce, ketchup, etc.
- unhealthy fats: processed vegetable oils, mayonnaise, etc.
- alcohol: beer, wine, liquor, mixed drinks
- sugar-free diet foods: sugar-free candies, syrups, puddings, sweeteners, desserts, etc.
Foods to eat
- meat: red meat, steak, ham, sausage, bacon, chicken, and turkey
- fatty fish: salmon, trout, tuna, and mackerel
- eggs: pastured or omega-3 whole eggs
- butter and cream: grass-fed butter and heavy cream
- cheese: unprocessed cheeses like cheddar, goat, cream, blue, or mozzarella
- nuts and seeds: almonds, walnuts, flaxseeds, pumpkin seeds, chia seeds, etc.
- healthy oils: extra virgin olive oil, coconut oil, and avocado oil
- avocados: whole avocados or freshly made guacamole
- low carb veggies: green veggies, tomatoes, onions, peppers, etc.
- condiments: salt, pepper, herbs, and spices