The ketogenic diet, or keto diet, is a very low-carb, high-fat diet. By reducing your carbohydrate intake and substituting it with fat, you can use this diet to induce a metabolic state known as ketosis. Typically, your body’s cells use glucose as their main form of energy. Glucose is derived from sugars or starchy foods, and is converted to energy or stored in the muscles and liver as glycogen[1]. If your body has insufficient glucose reserves to meet energy demands, it will go into the metabolic state known as ketosis, where the body begins to break down stored glycogen and fat to use as energy.
The Ketogenic Diet
The ketogenic diet aims to take advantage of the breakdown of fats for energy by creating this metabolic state to induce weight loss. In some instances, the keto diet can be more effective for weight loss than a low-fat diet[2]. The substitution of fat from carbohydrates causes your body to turn fat into ketones , which are released into the bloodstream to provide energy. A ketogenic diet may also lower blood sugar and insulin levels[3].
There are several different types of keto diets, including:
- Standard ketogenic diet (SKD): This is the most popular type of keto diet. You maintain a minimal carb intake (5 percent), moderate protein intake (20 percent) and high fat intake (75 percent)[4].
- Cyclical ketogenic diet (CKD): This form of the keto diet is used to promote muscle growth. It involves 5-6 days of standard ketogenic dieting, followed by 1-2 days of high carb intake.
- Targeted ketogenic diet (TKD): For this diet, you alternate periods of high and low carb intake based upon your training regime.
How a Ketogenic Diet Can Help You Lose Weight
When you start using a very low-carb diet, your body will not begin using ketones as an energy source immediately. It usually takes around 48 hours for your body to switch from leftover carb-to-energy conversion to fat-to-energy conversion.
As your body begins to break down fats, fatty acids and glycerol are burned off by the liver in a process called beta-oxidation. The resulting ketones are used to fuel the muscles and brain. In the state of ketosis, your body has an extremely high fat-burning rate, so you should begin to see in increase in weight loss[5] in about one month. Several studies have shown that people on a ketogenic diet lose significantly more weight than those on a low-fat diet[6][7].
Ketosis as an Appetite Suppressant
Ketosis may help you suppress your appetite in more than one way:
- Preventing blood sugar swings: Cutting out carbs can reduce hunger-causing fluctuations in blood sugar levels[8].
- Increasing satiety levels: When you lose weight, your body produces less cholecystokinin (CCK) – the hormone that makes you feel full. Even when you’re losing weight, ketosis can return CCK to pre-weight loss levels[9].
- Reducing appetite: Ghrelin is known as “the hunger hormone” because it increases appetite. During ketosis, the increase in ghrelin due to weight loss is suppressed[10].
How to Use the Ketogenic Diet for Weight Loss
If you wish to use the keto diet for maximum weight loss, you should break your meals down so that your fat intake makes up 70-80% of total calories, your protein intake 20-25% of total calories, and your carb intake 5-10% of total calories.
When you’re ready to plan your grocery trip, here is a list of foods that you can choose from:
- Meats: Pork, beef, lamb, poultry, veal and fish.
- Dairy products: Cream, yogurt and cheeses.
- Eggs
- Low-carb vegetables: Spinach, pepper, Brussels sprouts, kale, onions, and broccoli.
- Fats and oils: Olive oil, sesame oil and oil made from nuts and seeds.
- Low-sugar fruits: Avocados, raspberries, blueberries, and strawberries.
- Herbs and spices with no additives.
Make sure to look for fresh produce whenever possible, and steer clear of the following:
- Carbohydrates: Whole grains, fruits (except berries), beans and legumes (they are still starchy, even as a protein), white potatoes, parsnips, carrots, and peas.
- Processed foods: Refined sugars, refined grains, flour-based goods, pasta, bread, juice and soft drinks, low-fat diet foods.
Low-carb Drinks for the Ketogenic Diet
If you’re looking for low carb drinks to complement your ketogenic diet, try these:
- Water: You can drink either still or carbonated water but should avoid water that is flavored with fruit juice. Jazz up your water with cucumber, mint, rosemary, or lime.
- Tea: You can drink as much tea as you like. Green tea is particularly beneficial. Dry herb or spice teas for a refreshing change. You may also find them easier to drink without milk or sweeteners.
- Coffee: Like tea, you can drink coffee as often as you like. Try coconut milk and ice to chill out your coffee.
- Alcohol: If you must drink socially from time to time, liquor drinks such as whiskey, vodka, run, tequila, and gin do not contain carbs. You should avoid wine, beer, and mixers because of their carb content.
- Soda drinks: Soda drinks are okay, if kept to a minimum, as long as they are sugar-free. Don’t over indulge or they may trigger your sugar cravings.
Other Benefits of the Ketogenic Diet
As well as helping you lose weight, the ketogenic diet may also lower the risk of heart disease. Ketogenic diets may improve a number of risk factors for heart disease, including blood sugar levels, blood pressure and low density lipoprotein (LDL or “bad cholesterol”) levels[11]. A ketogenic diet may have therapeutic uses for cancer as cancer cells use carbohydrates for most of their energy[12]. Switching to ketones confers greater oxidative stress on cancer cells[13] and may also improve the anti-tumor effects of chemotherapy[14].
Some people begin the ketogenic diet with the best of intentions but find it difficult to maintain over time. Bear in mind that keeping up with a 100 percent ketogenic diet all the time may not be practical or desirable over the long term. There may be times that you have a period of higher carbohydrate intake, such as before you go to the gym. You also may experience an uncomfortably low level of energy if you are in ketosis for a long period of time. However, you can still take advantage of the ketogenic diet, by using it in a targeted cycle. This would mean eating keto for several days then having a two-day break where you eat a higher level of carbs.
There are many diets to choose from and the ketogenic diet is just one of them. In the short term, proper diet and exercise helps you control your weight but there are many long term benefits. Lower rates of high blood pressure, high cholesterol, metabolic diseases like diabetes are all reasons to start dieting and exercising today. These lifestyle modifications do not need to be drastic and can start as simple promises to yourself. You can start by swearing off potato chips or go for a short walk around the neighborhood once a day. People do slip from time to time but it is not a reason to give up completely on dieting and exercising. Reward yourself occasionally with a nice delicious smoothie or day off at the gym if you’ve been going regularly. We wish you the best of health.
[1] https://dtc.ucsf.edu/types-of-diabetes/type1/understanding-type-1-diabetes/how-the-body-processes-sugar/the-liver-blood-sugar/
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3826507/
[3] http://www.diabetes.co.uk/keto/
[4] https://www.ncbi.nlm.nih.gov/pubmed/14769483
[5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3826507/
[6] https://www.ncbi.nlm.nih.gov/pubmed/12679447
[7] https://www.ncbi.nlm.nih.gov/pubmed/17971178
[8] https://www.hsph.harvard.edu/nutritionsource/carbohydrates/carbohydrates-and-blood-sugar/
[9] https://www.ncbi.nlm.nih.gov/pubmed/18469245?dopt=Abstract&holding=npg
[10] http://www.nature.com/ejcn/journal/v67/n7/full/ejcn201390a.html
[11] https://www.ncbi.nlm.nih.gov/pubmed/22905670
[12] https://www.ncbi.nlm.nih.gov/pubmed/17313687
[13] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4215472/
[14] https://www.ncbi.nlm.nih.gov/pubmed/25666556
About the Author:
Dr. Bryan Do, D.O. is an osteopathic physician whose research interests include gastroenterology, immunology, and dermatology. He is particularly interested in the role of probiotics in the gut-brain-skin axis and has written many articles on the topic. He graduated from University of California, Los Angeles (UCLA) before graduating from Marian University College of Osteopathic Medicine in Indianapolis, Indiana and becoming a Doctor of Osteopathic Medicine. Osteopathic physicians are taught to take a holistic approach to medicine and to consider mind, body, and spirit when treating a patient. Osteopathic physicians receive training in Osteopathic Manipulative Medicine (OMM) in addition to the standard rigorous medical school curriculum. Both physicians with a Doctor of Osteopathic Medicine (D.O.) degree as well as a Doctor of Medicine (M.D.) can practice medicine.