By Nav Sharma, Registered Dietitian
What is the keto diet? Is the keto diet healthy? Is it true that I can eat all the fat I want on the keto diet? Is the keto diet safe to follow? Is the keto diet truly the best for weight loss? These are just a few of the questions we, as dietitians, frequently get asked about the infamous ketogenic (or better known as “keto”) diet. And normally these questions are followed by “My <insert: friend, family member, colleague, neighbour, uber driver…> lost 50 lbs on this diet.” Sound familiar? So what is the truth about the keto diet and does this diet ACTUALLY help with long-term weight loss?
Where Did Keto Come From?
Before we answer these questions, let’s go back in time for a moment. The keto diet was given its name in the early 1920s and became popular as a form of therapy for epilepsy in children in the 1920s and 30s. Since then, the keto diet has gained considerable attention as a potential weight-loss strategy due to the low-carb diet phenomenon, which started in the 1970s with the Atkins diet. And just in case you don’t know, the Atkins diet is a very low-carb, high-protein diet, which was a commercial success and popularized low-carb diets to a whole new level…
Why Do We Need to Lose Weight?
Okay, so why are we always trying to lose weight? Well, the prevalence of obesity has increased significantly in Canada over the past several decades. According to the 2014 Canadian Community Health Survey, over 5 million adults have obesity and based on the 2015 Canadian Health Measures Survey, 30% or more than 1 in 3 adults in Canada has obesity and may require medical support. It is also important to know that obesity is a leading cause of type 2 diabetes, high blood pressure, heart disease, stroke, arthritis, cancer and other health problems. Health is definitely an important consideration for weight loss but the other reason is that some people just want to feel more comfortable in their skin.
Back to keto! Want to know more? Keep reading to find out what the keto diet is, how the keto diet works, the truth behind the keto diet and weight loss, possible pitfalls of the keto diet and some things we still don’t know about the keto diet.
What Exactly Is the Ketogenic Diet?
The ketogenic (keto) diet is a high fat, moderate protein and low carb way of eating. The hope of the keto diet is to get into a state of ketosis, in which the body burns fat as a primary fuel source instead of carbohydrates. There isn’t one standard ratio of carbs, protein, fat for the diet. Instead:
- Carbs are typically reduced to 5-10% of your total daily calories (that’s typically less than 50g per day and can be as low as 20g)!
- Protein can range anywhere from 10-20% (~75g on a 2000 calorie diet)
- Fats should be between 70-80% (~165g on a 2000 calorie diet)
If you’re a frequent ‘dieter’, you’ve already probably noticed that many other diets promote high protein intake. That is because protein-rich diets can keep you full AND can help build lean muscle mass when combined with exercise. And for some, lean muscle can help with weight loss as lean muscle burns more calories than fat mass. However, the amount of protein recommended in the keto diet is only ‘moderate’ and not high because eating too much protein can prevent ketosis from happening. How? Protein building blocks called amino acids can be converted to glucose when eaten in amounts greater than what our body needs, and glucose, being a carbohydrate, prevents ketosis. In the keto diet, only enough protein is recommended to preserve lean muscle mass.
Side note: Did you know that how your body responds to protein depends on your genetics? Interested in knowing if a high protein eating plan would work for you? Find out by doing Nutrigenomix genetic testing! https://www.nutriprocan.ca/dna-testing-for-nutrition/
How Does the Keto Diet Work?
The keto diet deprives your body of glucose. And if you remember way back from your high school biology days, glucose is the main source of energy for all of the cells in our bodies and comes from eating carbs. Since our brains can’t store glucose, it requires a steady amount of glucose in the amount of 120-150g per day. When we are fasting (including sleeping) or eating low amounts of carbs, our body first accesses stored glucose from our livers. Once our glucose stores have completely depleted, the body begins to break down fat. During this process, the liver produces ketone bodies from fat which are then used as the primary source of fuel for the body. When the concentration of ketone bodies in the blood is high, ketosis occurs. We naturally experience mild bouts of ketosis when we are fasting, sleeping or participating in high-intensity exercises. How quickly ketosis happens and the level of ketosis varies from person to person.
Now, if everyone is talking about the diet, there has to be something good about it, right? Here are some of the potential SHORT-TERM benefits of following the keto diet according to research:
- Weight loss.
- Improvement of health markers associated with excess weight such as insulin resistance as well as high blood pressure, triglycerides and cholesterol.
- A potential strategy for type 2 diabetes.
How Does the Keto Diet Help with Weight Loss?
Okay, so we know that the keto diet DOES help with weight loss and there are many different theories as to why it works. Here are a few of them:
- Satiety. The high-fat content of the keto diet keeps people feeling full resulting in decreased food cravings.
- Hormones. Restricting the amount of carbs you are eating causes the appetite-stimulating hormones ghrelin and insulin to decrease.
- Ketone bodies. The ketone bodies produced from the breakdown of fat in our bodies have the ability to directly reduce hunger.
- Increased calorie expenditure. The process of converting fat and protein to energy in the keto diet burns more calories than converting carbs to glucose in higher carb diets.
- Fat loss. The keto diet promotes fat loss as opposed to building lean muscle mass due to lower carb intake (and therefore decreased insulin levels) and only moderate protein intake.
It is important to emphasize that research in this area has not been consistent which is why these are just theories for now…
How Long Should You Follow the Keto Diet?
Many programs suggest following it until the desired amount of weight is lost. Once you’ve reached your goal, you’ll want to follow it either a few times a week or a few weeks a month to prevent that well known post-diet weight gain.
Possible Pitfalls of Following the Keto Diet
Now that we know what the keto diet is about, here are some of the possible issues associated with the diet.
- Health risks. Following the keto diet long-term can be detrimental to your health. Some of the health risks include kidney stones, osteoporosis, and increased blood levels of uric acid (which could lead to gout). Due to potentially high levels of saturated fat from animal proteins, the keto diet may also increase cholesterol levels, a marker of heart disease.
- Hard to maintain long-term. Anybody who is on the keto diet will let you know that going keto isn’t easy. Those who follow the diet properly must strictly limit ALL carbs, cut many fruits and vegetables out, watch your alcohol intake and consume mostly fat. That means variety is low and some of your favourite desserts and juicy fruits are gone! In fact, research shows that compared to a low fat diet, those following the keto diet will experience an additional drop of 2 lbs over 1 year. However, how closely one can follow the diet will decline significantly after 1 year compared to those following a low-fat diet.
- Unpleasant symptoms. Some possible symptoms of extreme carb restrictions include hunger, fatigue, decreased moods/irritability, headaches and brain fog – this is called the “keto flu”. These symptoms could last days to weeks. OUCH! The elimination of fibre-rich grains and starchy vegetables may also lead to constipation and an imbalanced gut microbiome as many carbs include prebiotic foods.
- Nutrient deficiencies. The major nutrients missing from the keto diet include fibre, B vitamins, and minerals like iron, magnesium and zinc.
- Relationship with food. Like most restrictive diets, the keto diet may also negatively impact your overall relationship with food leading to behaviours such as emotional or binge eating.
Things We Don’t Know Yet About the Keto Diet
While we have discovered a lot about the keto diet in the past several years, here are some of the main things we don’t know yet.
- The long-term (one year or longer) effects and safety issues of the ketogenic diet.
- The diet’s health benefits and/or concerns when it comes to higher risk individuals with one or multiple health conditions and older adults.
- Different long-term outcomes of the keto diet based on the type of fat (saturated vs. unsaturated) consumed.
- The restrictiveness of the keto diet and its effects on periods of rapid growth or heightened nutritional needs including pregnancy, breastfeeding, athletes or during childhood/adolescence.
Ultimately, the keto diet sounds like just another weight loss strategy so far with many unknowns. Top that with how difficult it can be to follow long-term and it doesn’t seem like the most ideal solution to address your weight goal.
The best weight loss plan will always be the one you can follow long-term that includes foods from all food groups including lean proteins, fruits, vegetables, legumes, and dairy or alternatives.