Since I’ve started studying nutrition, hands down the most common question I get asked is about the ketogenic diet for weight loss. I’ve previously discussed this on my instagram story (@wellbymel_), but since I get asked this so often, I also wanted to write a blog post on this topic. This post will discuss the ketogenic diet and some considerations for the diet when used for the purpose of weight loss.
What is the Keto Diet?
The ketogenic diet is a diet that is characterized by high intake of fat, moderate intake of protein, and very low intake of carbohydrates. The standard keotgenic diet contains 75% fat, 20% protein, and 5% carbs (Mawer). That amounts to about 25 grams of carbohydrates per day (based on a 2000 calorie per day diet). For reference, a medium-sized apple contains about 25 grams of carbohydrates (Calorieking). The goal of the keto diet is to achieve the metabolic state of ketosis. Ketosis is when your body utilizes fat as its primary source of fuel instead of carbohydrates. The keto diet has been used in a medical setting as a treatment for frequency of epileptic seizures in children. However, it is commonly also used by the general public as a means of weight loss (Harvard Health Publishing).
Ketosis is different than ketoacidosis. Ketosis is the normal production of ketones (Mawer). Ketoacidosis is a very high concentration of ketones that changes blood pH and can cause a person to go into a coma and can even result in death.
It Is Difficult to Acheive Ketosis
It can take a couple of days for a person to get into ketosis. Eating too many carbs or protein can interfere with ketosis (Harvard Health Line). In order to determine if you are in ketosis, there are different tests available (urine test, blood test, etc). If you are trying to eat a keto diet, but are not in ketosis, you are essentially on a high fat diet. Fat is the most calorie-dense macronutrient. Fat contains 9 calories per gram. In comparison, protein and carbohydrates only contain 4 calories per gram. So if you’re trying to follow the keto diet, but are not in ketosis, you may be unintentionally eating more calories.
Vegetables Are Carbs
As discussed, the keto diet is a very low carbohydrate diet. Fruit is, of course, a carbohydrate. However, many people may not realize that vegetables are also carbs! One cup of raw broccoli contains about 6 grams of carbohydrates (Calorieking). One cup of raw brussel sprouts contains about 8 grams of carbohydrates (Calorieking). On the keto diet, intake of fruits and vegetables need to be limited in order to keep carbohydrate levels low. If you’re following the keto diet, you may miss out on all of the great nutrients in fruits and vegetables!
Fiber Is A Carb
In addition to vegetables, fiber is also a carbohydrate. Fiber is associated with a ton of health benefits. If you’re following the keto diet, you may miss out on the benefits of fiber!
Excess Saturated Fat Intake
The keto diet is a high- fat diet. My concern with a high-fat diet is excess intake of saturated fat. Saturated fat is associated with certain health risks. It can increase risk for heart disease, negatively impact cholesterol, and increase risk for type 2 diabetes (Harvard Health Publishing). When eating fats, it’s better to focus on healthier, unsaturated fats such as olive oil, nuts, and avocados.
On the keto diet or another low carb diet, you may notice lower numbers on the scale right away. Unfortunately, this initial weight loss could be due to water weight not fat loss. This is because the storage form of carbohydrates, glycogen, attracts water (because of the hydroxyl groups in its structure). So if you limit consumption of carbohydrates, you limit the amount of glycogen and water stored. This could be the cause of the reduced number on the scale (Samuels).
Mawer, Rudy. “ The Ketogenic Diet: A Detailed Beginner’s Guide to Keto.” Healthline, July 2018, http://www.healthline.com/nutrition/ketogenic-diet-101#what-it-is.
Publishing, Harvard Health. “Should You Try the Keto Diet?” Harvard Health, Oct. 2018, http://www.health.harvard.edu/staying-healthy/should-you-try-the-keto-diet.
Samuels, Mike. “Glycogen and Weight Loss.” LIVESTRONG.COM, Leaf Group, http://www.livestrong.com/article/307905-glycogen-and-weight-loss/.