What is the Ketogenic Diet?

The Ketogenic Diet was initially developed and used to treat children suffering from epileptic seizures, with more research indicating the efficacy in those with glioblastomas (a type of brain cancer). It is essentially a high-fat, moderate-protein, and very low-carbohydrate approach. Eating so few carbohydrates (typically under 50g per day) forces the body to use fat from the diet (rather than carbohydrates) as the body’s main source of fuel. Instead of glucose, which is derived from the carbohydrates we eat, the body relies on energy from ketone bodies derived from fat. After following this regimen for several days to a week, the body will be in what is called ketosis.

It is common to hear different definitions and criteria for what is considered “keto”. While there is no standard or strict criteria on what portion of calories from fat, carbs, and protein comprises the ketogenic diet, it is clear what isn’t keto. The ketogenic diet is not a “high-protein” diet. Whereas some other low-carb diets (such as the modified-Atkins diet) emphasize that as much as 30% of daily calories should come from protein, the protein content in many ketogenic diets is dialed back to around 10%. This leads to a very important claim of the diet; if protein intake is too high, the body has enough of the amino acids glutamine and alanine to convert into glucose, which can knock a person out of ketosis. However, the research on this claim is not well supported. Ketosis is a continuum, with an increasing number of ketones as with greater carbohydrate restriction.

The ketogenic diet is a high fat diet. Carbohydrate intake must be low enough to allow the body to use
ketones as fuel, and protein must be moderate but not too high in order to not disrupt ketosis. The most commonly used ketogenic ratio is 4:1, which describes a diet that is made of 4 grams of fat for every 1 gram of protein or carbohydrate. In other words, for every 5 grams of food consumed, there are 4 grams of fat and 1 gram of protein and/or carbohydrate. Someone who is aiming to adhere to the 4:1 ratio will have to use a gram scale for accuracy. A real-life example of this would be 1 gram of kalamata olives, which have 0.07g carbs, 0g protein, and .28g fat.

Why Is the Ketogenic Diet so Popular?

The ketogenic diet has seen a huge surge in popularity in recent years. Opponents of this diet argue that the popularity of this diet comes from historical popularity of Paleo, Atkins, and other carbohydrate-restricting meal patterns. Supporters of this approach state the high fat intake keeps you full and satisfied, and that the diet boosts energy levels and reduces or eliminates cravings. Many people struggle to limit portions with indulgent foods that contain carbohydrates and sugar, such as cookies, cake, doughnuts and potato chips. The ketogenic diet almost completely eliminates carbohydrates, therefore eliminating these food options. Being in a caloric deficit basically puts the body into what many call “starvation mode,” which inhibits weight loss from occurring.

We also know fat and protein make us feel fuller faster; for this reason some people argue that it’s easier to create a calorie deficit and not feel a strong sense of hunger while following the ketogenic diet. However, the studies that show following the ketogenic diet causing the feeling of being fuller faster are not as factual as they seem. Many are studies that do not allow enough time for accurate information to be provided, with appetite being self-reported; self-reported information is usually not very reliable in research.

Should I Consider the Ketogenic Diet?

While the ketogenic diet may seem enticing based on the proposed benefits, there are some red flags to consider.

The primary consideration is the basic logic of why the ketogenic diet is useful in those with epilepsy or glioblastomas (brain tumors): the keto diet starves the brain. For optimal functionality, a person should consume, on average, at least 130g carbohydrate daily to support brain and eye health. With keto, we find that starving the brain limits activity from the neurotransmitters (i.e. GABA) that cause seizures as well as starving ALL brain cells (including glioblastomas). If you deal with epilepsy or gliobastomas, a personalized ketogenic diet with the guidance of an experienced registered dietitian may be appropriate.

One study looked at data from about 400,000 people and concluded that those who ate high carb diets (over 70% of their calories from carbs, 45-65% is recommended) AND low-carb diets (under 40% of their calories from carbs) resulted in the SAME high risk of death. However, substituting a reduced carb diet with plant-based protein sources resulted in reduced risk of death. Interestingly, this was not the case for those who substituted their low-carb diets with animal-based protein. Another study, which was presented at the European Society of Cardiology Congress, reviewed data from about 25,000 people who participated in the NHANES (U.S. National Health and Nutrition Examination Survey). The data showed that those following a low-carb diet (under 40% of their calories from carbs) were 51 percent more likely to die from heart disease, 50 percent more likely to die from cerebrovascular disease and 35 percent more likely to die from cancer. The study concluded stating a diet in which 50%-55% of total energy came from carbohydrates was associated with the least risk of death compared to the other groups.

The ketogenic diet doesn’t just eliminate a food group, unlike the Paleo diet, for example, which excludes grains and legumes. It almost completely eliminates a nutrient: carbohydrates. Nutrient-dense foods including fruits, starchy vegetables, grains, dairy, beans/legumes and (to a mild extent) non-starchy vegetables all contain carbohydrates. People sticking to the ketogenic diet have to severely limit all of these food groups. There are two issues with cutting out so many food groups. First, it exposes a person to nutrient deficiencies if they don’t plan their food choices well, specifically the B vitamins, calcium, potassium, and vitamin K just to name a few. Developing nutrient deficiencies can create serious health problems, including anemia, weak bones and bone loss, poor immune function, and more. Second, cutting out so many food groups is likely to be unsustainable in the long term. Overall weight loss on keto, in the long term (1 year or longer), is shown to be minimal - likely due to poor long-term adherence and difficulty with even short-term compliance.

Always ask yourself whether you can see yourself following a nutrition plan for years to come- if not, reconsider! Research has shown it is not a good idea to “yo-yo” diet – going on and off restrictive ways of eating - there are many ways to boost energy levels, feel stronger, lose weight [if that is desired], and improve overall health. Achieving those goals is not about dieting, it’s all about finding sustainable strategies that work for you. A Registered Dietitian at The Sage can help you learn more about creating a sustainable plan for you to achieve your health goals. For more questions regarding the ketogenic diet and other nutrition topics, contact us and we’ll be happy to help!

Happy Eating!

Kamran Ahmad, MS, RDN, LDN

Edited By:

Zachari Breeding, MS, RDN, LDN, FAND

Kevin Klatt, PhD/RD Candidate

Tobias Levin, MLA