People either rave about the ketogenic low-carb diet or try to scare you off with claims that it will cause vomiting, confusion, and bad breath. How can you know what is true?
This article will give you a brief rundown on how the ketogenic diet works and give you a list of the benefits so you can determine if it might be right for you.
How Ketosis Works
The ketogenic diet is a very low-carb, high-fat diet that was first designed to treat epilepsy. By restricting carbohydrates in favor of fat, blood glucose levels fall and the body begins to burn body fat for energy. The liver turns fatty acids into ketones, which can be used to produce energy.
The general macronutrient ratios for a ketogenic diet are 75 percent fat, 20 percent protein, and 5 percent carbs; however, these can be modified based on individual needs and goals. For the initial adaptation phase, carbohydrate intake needs to be below 50 grams of carbs a day.
Ketosis Requires An Adaptation Process
One drawback to ketogenic diets is that they require an adaptation process so that you can readily burn body fat. This is one reason dietitians are so down on them. People often quit before fully undergoing adaptation, which is unfortunate because being “fat adapted” is essential if you want to stay lean and feel energized.
If you’ve been eating a high-carb diet, your body won’t have the necessary enzymes to effectively burn fat. In this environment, ketones will be at a level of less than 0.3 millimolar (mM).
In the initial stages of carbohydrate restriction, the body won’t burn the ketones that are produced by the liver. Instead, they will be excreted in the urine and via respiration (breathing out). During this stage, the body relies on glucose from glycerol and liver glycogen for energy.
Ketones have a fruity odor like acetone, which is one reason that some people associate ketogenic diets with bad breath. However, the smell is not the same thing as gum disease and it goes away once you are keto-adapted and able to burn ketones for energy.
Soon enough, ketone levels will rise above 0.5 mM and the body will begin to use those ketones in the Krebs Cycle to produce ATP. When ketones are at a level between 0.5 and 5 mM, you’re in a range called “nutritional ketosis.” This state is when the body has reached keto-adaptation and will utilize ketones and fatty acids as the primary fuel source.
What About Brain Fuel?
A favorite argument of detractors of the ketogenic diet is that it doesn’t provide sufficient glucose for the brain to function. It is true that the brain requires about 50 grams of glucose a day, but this doesn’t need to come from eating carbohydrates.
Rather, the body is capable of producing glucose from glycerol (from dietary fat or fat tissue in your body), lactate and pyruvate, (produced from glycolysis), and from amino acids (from protein). These substrates go to the liver where it turns them into glucose via the process known as gluconeogenesis.
The rest of the energy that the brain requires is derived from ketones. Having the brain get energy from ketones actually improves brain function and is the reason that ketogenic diets are used to treat brain disorders.
Now that you know the truth about how a ketogenic diet works, let’s look at some of the benefits:
Benefit #1: Fat Loss
Ketogenic diets blunt hunger, which is one of the hardest things about fat loss.
Benefit #2: Reduce Insulin Levels & Lower Diabetes Risk
Ketogenic diets lead to an automatic reduction in insulin as glucose levels go down and the body shifts into fat burning mode.
Benefit #3: Increase Fat Burning
Enzymes necessary for fat burning are increased and the body is better able to access fuel stores for energy.
Benefit #4: Lower Blood Pressure
Reducing carbohydrate intake leads to a significant reduction in blood pressure. Combined with the reduction in body fat that coincides with a ketogenic diet, people with hypertension often see blood pressure return to the normal, healthy range.
Benefit #5: No Calorie Counting
Because ketogenic diets lead to a drop in hunger, calorie counting is not necessary since people will automatically reduce food intake and create a calorie deficit.
Benefit #6: Lower Triglycerides
Triglyceride levels, which are the amount of fat in the blood, are a main predictor of heart disease. Triglycerides tend to be higher when a greater proportion of calories comes from carbohydrates, especially fructose. Counterintuitively, triglycerides go down on low-carb diets as metabolic function is restored.
Benefit #7: Improved Cholesterol Levels
One reason the mainstream is so down on ketogenic diets is that they are high in fat, often including a decent amount of saturated fat. However, saturated fat doesn’t cause heart disease, and when it is eaten with other healthy fats and plenty of low-carb green vegetables, you can experience an improvement in cholesterol levels. People often see an increase in HDL “good” cholesterol and either no change or a drop in LDL cholesterol from ketogenic diets.
Benefit #8: Lower Risk of Brain Disorders
Ketogenic diets are protective against epilepsy and may help reduce the risk of other brain disorders such as Alzheimer’s and Parkinson’s.
Benefit #9: Reduce Belly Fat
Because of how they improve balance of insulin and other metabolic hormones, ketogenic diets are your go-to method for losing dangerous belly fat.
Benefit #10: Increased Endurance Performance
Although a ketogenic may not be appropriate for every endurance athlete, emerging research shows that by adapting the body for fat burning, you can increase your performance at long durations.
Baba, H., et al. Glycerol gluconeogenesis in fasting humans. Nutrition. 1995. 11(2):149-53.
Bueno, N., et al. Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomized controlled trials. British Journal of Nutrition. 2013. 110(7):1178-87.
Johnstone, A., et al. Effects of a high-protein ketogenic diet on hunger, appetite, and weight loss in obese men feeding ad libitum. American Journal of Clinical Nutrition. 2008. 87, 44–55.
Krilanovic, N. Benefits of Ketogenic Diets. American Journal of Clinical Nutrition. 2007. 85:238–43.
Owen, O., et al. Brain metabolism during fasting. The Journal of Clinical Investigation. 1967. 46(10).
Paoli, A., et al. The Ketogenic Diet and Sport: A Possible Marriage? Exercise and Sports Science Reviews. 2015. 43(3):153 162.
Paoli, A., et al. Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. European Journal of Clinical Nutrition. 2013. 67, 789-796.
Paoli, A., Grimaldi, K., et al. Ketogenic Diet Does Not Affect Strength Performance in Elite Artistic Gymnasts. Journal of the International Society of Sports Nutrition. 2012. 9(34).
Veech, R.L. The Therapeutic Implications of Ketone Bodies: The Effects of Ketone Bodies in Pathological conditions: Ketosis, Ketogenic Diet, Redox States, insulin Resistance, and Mitochondrial Metabolism. Prostaglandins, Leukotrienes, and Essential Fatty Acids. 2004. 70(3), 309-319.