I am so, so tired of hearing about the ketogenic diet. I am tired of being asked about it, I am tired of people thinking it’s some miracle diet that cures everything, I am tired of reading about it and seeing Facebook and insta posts about someone’s awesome keto meal, or how they ate _____ and didn’t bring themselves out of ketosis. I am tired of it. It’s old news, and in my personal opinion, it’s crap.
I am tired of it mostly because I have been reading post after post, blog after blog, article after article and about 100 evidenced based, tightly controlled journal articles for almost a year now about the diet to share with you all to enlighten you on the facts. With so many posts, I was hoping I could just share one with you. Unfortunately, no one post put it all together with all the points and facts I wanted, so here I am, gathering my research and writing to you.
For the purpose of this blog I am writing in reference to body composition and weight loss. I will not be touching on the other medical uses of the diet such as treatment of epilepsy in children and the new and upcoming research of its use in cancer, Alzheimer’s Diseases, Parkinson’s Disease or Multiple Sclerosis. I will also not be touching on the subject in its management of Type 2 Diabetes. As a Certified Diabetes Educator who has worked with hundreds of clients in the management of their disease with both lifestyle and medication, I am well aware that if someone living with diabetes does not consume carbohydrate their blood sugar will decrease and they will likely not need as much insulin and/or medication. That’s just common knowledge of basic metabolism. After working with these hundreds of clients and coaching them to reduce their carb intake to 45-60g PER MEAL, I know it’s not sustainable or realistic to cut it out entirely or to a mere 50g or less PER DAY, and if you know me, you know I’m all about sustainability and realistic goals. I Digress.
What is the ketogenic diet?
Essentially, the goal of the diet is to put your body into ketosis. Ketosis is when your liver turns fat and certain amino acids into ketones to fuel your body because little to no (less than 50g) carbohydrate is available. As your Certified Diabetes Educator, I must add: dietary ketosis is NOT diabetic ketoacidosis, so let’s not make that mistake or get those two things mixed up. Without going into great detail, people who produce insulin don’t go into ketoacidosis, which can be fatal, the key here is the ACID in ketoacidosis compared to just ketosis.
One of my biggest issues with the ketogenic diet is that it’s really hard to sustain. It takes A LOT of effort to count all those grams of fat and carbohydrate. Remember, even your non-traditional carbohydrate foods have carbohydrate, so they need to be accounted for to keep yourself below that 50g.
1 cup Broccoli= 3.93g CHO
8 Medium Baby carrots = 6.59g CHO
1 cup celery = 3.89g CHO
1 Whole Egg = 0.92g CHO
1 Whole Avocado= 17.15g CHO
So, you literally spend your day measuring everything and then probably googling carbohydrate content, and then adding it all up; sounds exhausting, to say the least. Some people go the other way though, avoid the healthy veg and fill up on fat, but even they can have some hidden carbohydrate! Your one slice of pan fried bacon has 0.26g CHO, which isn’t a lot and for the normal person who eats maybe 2-3 slices in a meal, not a big deal. The average 500g package of bacon, however, has 9.6g CHO, which I am told is not uncommon for someone on the ketogenic diet to consume in a day (or I guess a meal). That’s already 1/5 of your daily allowance!
(I am sure there are many who balance it well, but the point here is that it’s still a lot of work)
Now, let’s talk about the importance of carbohydrate, the main macronutrient the ketogenic diet essentially eliminates.
Carbohydrates are known as the gold standard of food energy for the body. Cells function their best when they receive a certain level of carbohydrate (Health Canada says minimum 130g, this has been debated) in the form of glucose. You see, all the carbohydrate you eat, whether it be from bread, an apple or ice cream will turn into the glucose in the body. The brain, nervous system and red blood cells rely exclusively on glucose for fuel, and because glucose is ever so important we have two hormones that regulate it, insulin and glucagon. There is some glucose which is stored in the liver as glycogen, this covers you while sleep or miss a meal and some that are stored in your muscle. These are here for when the blood glucose levels get too low, which can be dangerous and to provide fuel to your brain. How might these stores get refilled you ask? You need to eat, and you need to eat carbohydrate.
When carbohydrates are inadequate in the diet the body needs to become creative in how to make energy and turn the available fuel it has into energy for your body’s mechanisms. Protein, mainly from muscle will get taken apart and converted into energy, not surprisingly, it gets turned into glucose (you know, your body’s fav fuel.) Some think that pairing this with a higher protein diet will help with muscle wasting, but it doesn’t, protein essentially just becomes an expensive source of fuel, rather than its intended use in the body as a building block. Protein is meant to maintain and build your muscles, hormones, enzymes, and cells in the body, it really shouldn’t be used for fuel.
The next logical step after using all of our glucose stores and breaking down our muscle is to start to burn fat. This is the whole concept of the ketogenic diet, eat fat to burn fat. However, only a small amount of the stored fat in our body can be converted to a carbohydrate fuel, and since we have some specific organs that only want glucose as fuel, we have a lot of enzymes to break down our protein and convert it to glucose.
So, why do people lose weight so well? That my dear is water weight. For every one pound of body protein you use, the associated 3-4 pounds of water is also lost. See-yah water weight! Now don’t get me wrong, eventually, the body will convert stored fat into a usable energy source for the brain and nervous system, because really… your body doesn’t want to die so it’s got some tricks up its sleeve, it will make ketones. Ketosis is an adaptation the body makes after prolonged fasting or carbohydrate deprivation. However, only about half of the brains cells can use ketones as fuel, so protein is still being wasted to maintain energy for the other half and most of the nervous system in the process known as gluconeogenesis, where protein is converted into the glucose as mentioned above.
So, what does the research say?
In March 2016 the results of the recent metabolic ward study by Hall et al showed that ketogenic diets don’t seem to provide a metabolic advantage or result in a higher rate of fat loss when compared to isocaloric non-ketogenic diets with equal amounts of protein.
However, this was not new news… not a new discovery and was actually a conclusion that was established back in 1976. That’s right folks, 1976, when the first metabolic ward study was completed which compared ketogenic to non-ketogenic diets and was published in the Journal of Clinical Investigation.
At the time, it was really only being used to treat epilepsy in children, us Dietitians were teaching it all the time! There were, however, no studies that directly compared the effects of a hypocaloric ketogenic diet to a hypocaloric non-ketogenic diet on body composition in a metabolic ward setting (gold standard testing right there).
This was what Mei-Uih Yang and Theodore VanItallie from the Department of Medicine and Institute of Human Nutrition of the Columbia University’s College of Physicians and Surgeons set out to investigate.
What they did:
Six obese male subjects, subjected to a metabolic ward setting for 50 days. The subjects completed 10 days of the following three experimental schedules, each preceded by a 5-day 1200-calorie mixed diet:
- 800-calorie ketogenic diet
- 800-calorie non-ketogenic diet
- starvation diet
(We won’t discuss the starvation diet, as it doesn’t affect my sole purpose of discussing Keto)
With regards to the diets, they were all liquid-based diets and were served to the subjects in four isocaloric feedings at 8:00 am, 11:00 am, 1:00 pm and 6:00 pm.
The composition of the diets was as follows:
- 800 calories
- 50 grams of protein (25%),
- 62 grams of fat (70%) and
- 10 grams of carbohydrates (5%).
- 800 calories
- 50 grams of protein (25%),
- 27 grams of fat (30%) and
- 90 grams of carbohydrates (45%)
Body composition was assessed using the energy-nitrogen balance method, which, essentially, uses the measurement of nitrogen balance to estimate changes in body protein content and then uses energy balance measurements to estimate changes in body fat.
As you can see, the study’s methodology has a few extremely important strong points which makes this a very strong study with valid results.
- The subjects spent the entire 50 days in a metabolic ward and had their meals prepared for them, which means that under and over reporting of food intake is not a concern as with all free-living studies.
- The ketogenic diet and non-ketogenic diet were isocaloric – their caloric content was exactly the same.
- The protein intake was matched between groups – this is vital since protein has a high thermic effect which, if not taken into consideration, will distort the results.
So, what were the results?
Both the ketogenic diet and the non-ketogenic diet resulted in statistically identical changes in body composition, although the ketogenic diet caused more weight loss which, according to the data, was entirely attributed to water weight loss.
“…the increment in weight loss exhibited during the ketogenic diet period was due solely to excretion of excess water. Rates of fat loss were not significantly affected by the composition of the diet.”
So, we have had a metabolic ward study completed 1976 which compared a ketogenic diet to a non-ketogenic diet while controlling for caloric intake and protein intake and it showed absolutely no differences in fat loss between the two.
In another laboratory setting changing the fat content of people’s diet actually resulted in them consuming 15% more calories on a diet that provides 45-50% from fat, compared to a moderate fat diet providing 30-35%, over a two-week period, this was statistically enough to promote weight gain.
Conclusion: I revert back to my original personal opinion. We have a gold standard, metabolic ward studies which indicated the ketogenic diet compared to a non-ketogenic diet promoted no additional fat loss. Wait, isn’t that the goal?
I have a few other beefs with what the research shows on high-fat diets as well. Research has implicated that a high-fat diet is a causative factor in the development of leptin resistance, a state in which the brain has a difficult time recognizing how much fuel is in the body. Leptin resistance favours weight gain over time, which is not the end goal here. Exposure to a diet with greater than 40% of calories from fat has been shown to weaken the body’s sensitivity to other hormones as well, such as CCK and GLP-1, both of which are essential to feeling full and satisfied after a meal.
Fat also impacts the reward circuits and pleasure sensors in our brain. Functional MRI studies have shown that when we eat fat-containing foods, it activates the parts of our brain which light up when you do something rewarding. At moderate intakes of fat, this really isn’t an issue, but chronic high dietary fat intake actually decreased dopamine signaling in the brain, muting your reward circuit. Experts in neurochemistry have postulated that this dulling of the reward value of food will leave a person unfulfilled, constantly chasing the type of food, typically hyperpalatable food that will release dopamine and give the reward sensation, these foods being high in fat, salt, and sugar.
So, would I recommend the ketogenic diet to someone?
No, but honestly, I don’t recommend any diet for weight loss, because in general diets are unsustainable. Pair that with the fact that the ketogenic diet is not superior in altering body composition, and it’s also messing with your brain signals, I just can’t jump on board.
If you want some strategies and support to help you reduce your carbohydrate intake and continue to live a satisfying life, if you want to re-learn how to get in tune with your hunger signals and how to regulate your intake based on hunger and not caloric value, if you want to live your best life by following your best diet to achieve your best weight, I’ll help with that!
If you REALLY want to follow a ketogenic diet or any other diet for that matter, I am here to support you in a non-judgemental way, but know we’re going to chat about the research and know that my goal for you is for you choose the lifestyle that best suits you, that is realistic and that is sustainable. If the ketogenic diet is not sustainable for you, I wouldn’t suggest you try to follow it, your motivation and drive will be diminished when you gain the water weight back once you being eating regularly again, and I get reeeeeal upset when clients think they failed.
I’m here, I’m rooting for you, and I know there is a lifestyle out there suited to you which helps promote weight loss and most importantly, makes you feel your best