The Ketogenic Diet and Weight Loss- What a Dietitian Thinks

Ketogenic diets seem to be all the rage recently. When I scroll through my Instagram, there are whole pages committed to this “diet”. So what exactly is a ketogenic diet? Most people falsely believe that a ketogenic diet is a high protein diet. This is not true. A ketogenic diet is a high fat diet. While the ketogenic provides adequate protein, it is extremely low in carbohydrates. Typically, only about 20-60 grams of carbohydrates per day are consumed. To put this into context, Health Canada recommends consuming, at a minimum, 130 grams of carbohydrates per day. To stay below this 20-60 grams of carbohydrates, high carbohydrate foods are exchanged for high fat foods.

The carbohydrate recommendations are so low in this diet that you really don’t have room for any predominantly carbohydrate foods. Even low carbohydrate foods contain some carbohydrates, and these can add up quickly to the 20-60 grams of carbohydrates. For instance, ¼ cup of almonds contains about 2.5 grams of carbohydrates.

The ketogenic diet was originally created to reduce the occurrence of epileptic seizures. While it’s still used for this clinical purpose, it is now commonly used for weight loss purposes. The reason that the ketogenic diet is promoted for weight loss is because of a process known as ketosis. Normally, carbohydrates are the preferred energy source for fuel. However, when carbohydrates are not available, such as when following on a ketogenic diet, the body switches to ketosis to provide the body with fuel. This is achieved by turning fat and certain amino acids into ketone bodies that your body can then use for energy.

One of the reasons that ketogenic diets help with weight loss is that ketone bodies reduce appetite. Other benefits include reduced blood sugar and blood insulin levels. Also, with such limited food options, of course you are going to eat fewer calories (there’s only so much avocado and butter you can eat). On the other hand, ketogenic diets are very low in fibre, which can lead to constipation. Ketogenic diets can also cause many negative side effects such as headaches, fatigue and nausea due to the process of ketosis. Those following a ketogenic diet will also likely miss out on many important nutrients since so many foods, such as fruits and grain products, are being totally excluded.

While this diet may be appropriate for sedentary individuals, it certainly is not a good option for most athletes. Research confirms again and again that a diet containing adequate carbohydrates is the best for optimal athletic performance. I repeat, almost all research supports a high carbohydrate diet for athletes. Of thousands of research articles, only a couple have supported low carbohydrate diets. Unfortunately, these very few studies are the ones that get blown up in the media despite a dominant majority still supporting high carbohydrate diets for performance. If you want to follow solid evidenced based research, eat carbohydrates.

Will you lose weight on a ketogenic diet? Yes. When starting this diet, some of this weight loss will be water weight rather than body fat. Carbohydrates are stored as glycogen in the body. Glycogen stores water along with it. When switching to a ketogenic diet, you’ll diminish your glycogen stores and the water stored along with it, contributing to a reduced weight.

While you’ll most likely lose weight in the short-term on a ketogenic diet, the real question is will you keep it off? As soon as you switch back to a “normal” diet, you’ll most likely gain back the weight and in most situations, a little bit more weight. This is yo-yo dieting and it can have negative consequences on your metabolism and make it harder to lose weight in the future. The ketogenic diet is an extremely strict diet and for most people, following it forever is just not realistic. Another big concern is that it can promote disordered eating and an over obsession with food. For most people, the best diet is the one that you don’t know you’re on, that can be sustained with little effort.

My August nutrition newsletter will be going out in a couple of days. You don’t want to miss the month’s newsletter. I explore the number one reason that I see clients struggle with weight loss, and strategies to overcome this. To receive this newsletter go to megankuikmanRD.ca, scroll to the bottom of the page and enter your name and e-mail address.