You may have noticed that the ketogenic (or “keto”) diet has soared in popularity in the past few years (take one quick look at a cookbook aisle and keto recipes abound). Despite the hype, this high fat, low carbohydrate diet is hardly new.  Since the 1920s, dietitians and medical professionals have recommended the keto diet as an effective treatment for severe childhood epilepsy (and they still do). It’s only recently that the ketogenic diet has been popularized by social media and the wellness industry for its promise of weight loss. But is this diet a good fit for you? 

What is the Ketogenic Diet?

The ketogenic diet is a high fat and low carbohydrate diet. In this diet, 75 percent or more of your energy is meant to come from dietary fat and less than 5 percent from carbohydrates (for comparison, the Health Canada Dietary Reference Intakes typically recommends that 45-65 percent of our energy comes from carbohydrates and 30-40 percent from dietary fat). 

Carbohydrates (glucose) are the body’s preferred source of energy, so when carbohydrates are scarce the body kicks off mechanisms to prevent starvation – enter ketosis. In ketosis, the body begins to adapt to its lack of carbohydrates and break down fat for fuel.  It is important to note that the keto diet is not a high protein diet (it’s high fat) – and in fact too much protein may actually kick people out of ketosis.

Why is it so popular? 

 So we’ve established what the keto diet actually consists of. But why is it such a popular weight loss solution in the media? Available research shows the ketogenic diet may have some beneficial metabolic changes in the short-term. In the short-term participants of studies have experienced improved blood pressure, blood lipid levels and weight loss.

When people first embark on a ketogenic diet (or any diet for that matter) typically there is a honeymoon period where individuals are losing weight at a fast rate. This is explained through the use of the body’s glycogen (stored energy) stores and water loss. When we reduce our intake of carbohydrates the body uses glycogen (stored glucose) from our muscles for energy. Glycogen contains water; therefore, as glycogen is used, water is also depleted and individuals see the number on the scale go down. Available research on the ketogenic diet for weight loss remains limited. There are many unanswered questions related to long-term effects of the ketogenic diet. In the short-term there have been some benefits, however, after one year, when compared to the effects of other weight loss diets, are not significantly different.

What are the drawbacks? 

There are pitfalls to restrictive diets, including the ketogenic diet. This diet eliminates a major food group which also reduces intake of certain vitamins and minerals (e.g. sodium, chloride, potassium, vitamin D, calcium) and eliminates many nutritious foods such as beans, legumes, whole grains, potatoes and fruit. Given the restrictive nature of this diet, it may encourage disordered eating behaviours and social isolation.  

Often, when people choose to eliminate carbohydrates from their diet they experience “flu-like” symptoms, that include, headache, irritability, foggy brain and nausea.  This phase of the ketogenic diet has been dubbed the “keto-flu”. These symptoms are not surprising as the body enters “survival mode” to prevent starvation and adapts to breaking down fat for fuel in place of carbohydrates. The keto diet may pose potential risks for those with health conditions such as diabetes, thyroid disorders or any conditions involving the pancreas, gallbladder and liver. It may also cause a decrease in blood pressure which may be potentiated by medications used to lower blood pressure.

Lastly, food is meant to be pleasurable and enjoyable. When thinking about embarking on a new eating pattern or diet, consider how it will impact your day to day life, socialization and sustainability. Can you see yourself eating this way for years to come? Sustainability can be one of the most important factors to consider; research shows restrictive diets may result in fast short term weight loss, however most gain it all back in the long term. This concept is known as weight cycling, it has negative health effects that include chronic inflammation, increased risk of cardiovascular problems and higher mortality from all causes.

Nutrition is unique to every individual, and there is no one size fits all. To find a way of eating that is health-promoting, and brings you joy and connection, consider reaching out to a weight-inclusive dietitian for support.