Ketogenic Diet
The Ketogenic Diet: Explained
What exactly is the ketogenic diet?
The ketogenic diet is a pattern of eating that is very low-carb, moderate-protein, and high-fat. The standard ketogenic, or “keto” macronutrient breakdown is typically 75% fat, 20% protein, and 5% carbs. The goal of this diet is ultimately to obtain “ketosis” which can occur in starvation, periods of fasting, and in very low carb diets. This diet was originally developed for treatment of epilepsy in the pediatric population but has since become sensationalized into a popular diet for weight loss.
What do you eat?
Since a vast majority of carbohydrates are eliminated from this diet, this leaves fat and protein sources. Foods that are high in fat and protein include most animal food sources. Therefore, a typical ketogenic diet includes large amounts of red meat, eggs, poultry, processed meats, cheese, oils, butters, nuts, etc. Fruits are almost entirely prohibited and vegetables are restricted, since both contain a good amount of carbohydrates (for example, one medium-sized banana can contain around 27 grams of carbohydrates). Some non-starchy vegetables such as leafy greens and cruciferous vegetables are allowed due to their low carbohydrate content. Carb-rich foods like beans, legumes, potatoes, and starches from both refined and whole grains like breads, rice, and pasta are typically not allowed.
How does it work?
Ketosis is achieved when ketone bodies are produced from fat stores and used for energy instead of glucose, which is the body’s preferred source of fuel. When we consume carbohydrates, the body converts carbs into glucose which circulates in our blood stream, acting as energy for our cells and muscles to use. In the absence of glucose, the body is forced to look elsewhere for fuel to sustain our everyday activities. Fat is eventually broken down to create ketone bodies, which then act as the new source of energy in the body. The body may reach a state of ketosis with an intake of about 20-50 grams of carbohydrates per day, but it’s important to note that this is a highly individualized process.
What research says
Current research so far does support that the ketogenic diet may be beneficial for weight loss short-term. The theories as to why it can promote weight loss include: increased satiety due to the high-fat content of the diet, a decrease in hunger hormones, and promotion of fat loss versus lean body mass. It is important to note that the long-term effects of this diet are currently inconclusive. People often see quick weight loss results with the ketogenic diet and other carb-cutting diets for the following reason: carbs are stored in the body as glycogen with water. Cutting carbs leads to fast weight loss because you lose a good amount of water weight initially, which comes from your glycogen and water stores.
Potential risks
This diet is very restrictive, making it difficult to follow long-term. It may create a negative relationship with food which can lead to a sort of “restrict-binge” mentality and cause eventual weight regain. From a health standpoint, this diet is rich in animal protein sources and saturated fats. The American Heart Association recommends that we restrict our intake of saturated fats to less than 10% of our daily intake, since it is linked with increased LDL cholesterol (bad cholesterol), which puts us at increased risk for developing heart disease. Other possible risk factors include development of kidney stones, osteoporosis, and exacerbation of preexisting liver conditions.
Consensus
As nutrition professionals, we generally recommend a well-balanced diet, one which includes fruits, vegetables, protein, dairy, and carbohydrates sources. A diet rich in each of these groups will provide adequate nutrition. Weight loss is ultimately achieved when there is a calorie deficit. Therefore, many people who follow the ketogenic diet may not actually be in ketosis. They may just be eating less carbohydrates and therefore less calories, which is attributed to weight loss. So, the question is, do you need to follow a ketogenic diet in order to lose weight? No! A well-balanced diet with a calorie deficit can help you achieve these same goals, without cutting out any food groups.
By Ariana Wood and Alexa Tillis
University of Saint Joseph
References:
https://www.health.harvard.edu/staying-healthy/should-you-try-the-keto-diet
https://www.health.harvard.edu/staying-healthy/the-smart-way-to-look-at-carbohydrates
http://columbiasurgery.org/news/2015/05/08/crunch-cruciferous-veggies
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3945587/
https://www.hsph.harvard.edu/nutritionsource/healthy-weight/diet-reviews/ketogenic-diet/