The most popular fad diet right now is the ketogenic diet; a high-fat, very low carbohydrate diet that was developed in the 1920’s to treat children with epilepsy. In pediatric epilepsy the cellular transporters of glucose in the brain are mutated causing seizures. When these kids are given the ketogenic diet, they are consuming high amounts of fat and little to no carbohydrates so instead of using glucose as an energy source they are using the products of fat metabolism and the glucose transporters are utilized less, resulting in less seizures. (1) Recently though the general public has come across this concept and translated it to weight loss. The first occurrence of this diet was in the early 2000’s and it was referred to as the Atkins Diet as it was introduced to the public by Dr. Atkins. Within the last few years it has resurfaced at the Keto Diet. The main idea behind the fad diet version is that by consuming little to no carbohydrates you are forcing your body to burn more fat, so in turn you should experience more fat weight loss. (2) Unfortunately, that’s not exactly how it works. Yes, the amount of fat your body is burning is greatly increased when you start the keto diet; but the amount of fat you are consuming is also greatly increased. And after being on the diet the rates of body fat burned are going to slow. This is because carbohydrates are our bodies preferred fuel source, and when you are barely consuming any carbs like on the keto diet, your body switches to the next preferential fuel source; protein. So, after a few weeks on the diet you are consuming more fat than your body is burning, and your body is going to start breaking down proteins to fuel you causing you to lose muscle mass and experience a decrease in weight loss. Due to the extreme reduction of carbohydrates you are also putting your body into ketosis. When you are eating predominately fats your body breaks them down into products called ketones. The brain can then use these as a fuel source since it isn’t receiving any glucose due to no carbohydrates being consumed. When this occurs for long periods of time the body is processing fats into ketones quicker then the brain can use them, and the blood and brain become flooded with ketones making them both extremely acidic and causing the state known as non-diabetic ketoacidosis.3 Ketosis and ketoacidosis are conditions that can occur in those with untreated diabetes, alcoholism, and renal failure and can be life threatening. The keto diet is potentially putting your body in this dangerous state voluntarily. The keto diet can also be harmful for your heart health as the main source of food in the diet is saturated fats; which are associated with a buildup of plaque in the arteries leading to heart disease. (4)
So even though we know all these bad things can occur when eating a ketogenic diet, why do people still do it? Because people like to focus on the positives. The keto diet does provide weight loss at the start of the diet and this gives people false hope. By the time the ketosis effects start to happen, and the weight loss is diminished most people have already ended the diet, as fad diets are hard to keep up with and have a high drop out rate. There also isn’t any research on the long-term effects that this diet has since again, most people don’t keep up with it for long enough and it would be unethical to put a group of people on the keto diet long term and subject them to ketoacidosis. Overall its important to remember that the keto diet is just another “yo-yo” fad diet and isn’t going to be the key to a long healthy life. Instead of focusing on fad diets try to eat a balanced, unprocessed diet that is filled with fruits, vegetables, whole grains, nuts/seeds, lean meats, and fish along with exercise to lose weight and sustain a healthy lifestyle.
1.) Barañano, Kristin W, and Adam L Hartman. “The ketogenic diet: uses in epilepsy and other neurologic illnesses.” Current treatment options in neurology vol. 10,6 (2008): 410-9. doi:10.1007/s11940-008-0043-8 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2898565/)
3.) von Geijer, Louise, and Magnus Ekelund. “Ketoacidosis associated with low-carbohydrate diet in a non-diabetic lactating woman: a case report.” Journal of medical case reports vol. 9 224. 1 Oct. 2015, doi:10.1186/s13256-015-0709-2 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4591635/)