In a nutshell: Ketosis is where our bodies use a different pathway to create ATP (energy), because we deprive it of carbohydrates (it’s preferred energy source). Instead, we flood it with fat so that the body rapidly breaks fat down to produce ketone bodies. These ketone bodies enter the citric acid cycle (energy production line) so that our cells can use them for energy.
This process is a survival mechanism our bodies have wisely developed to deal with starvation for times of famine. Despite this, we do need to maintain some level of glucose in the blood, simply to stay alive. Again, our bodies are very clever and have methods to deal with this, primarily through gluconeogenesis: fat / amino acid breakdown to create glucose. Another tidbit to note is that glucose is not just the preferred fuel for the body, it is actually the only fuel for certain vital functions (thus gluconeogenesis is crucial).
What is key here, at least to me, is the word survival. Our bodies main goal is to keep us alive. Forget optimal, or energetic, just simply alive and breathing. So when we enter ketosis, we are essentially working against our bodies natural and preferred function.
Do we know better?
Are we trying to trick our bodies?
This just seems fishy, because why would we try to teach the body something it innately knows, has been doing since our birth and does without question? It seems counterintuitive. It goes hand-in-hand with the fact that as humans, we love to interfere because we think we know a better way, or further, can “cheat the system”.
Something to think about… As ketones are not the preferred energy source, would ketosis not be a less efficient way of creating energy? As I mentioned, these survival mechanisms keep us breathing but not necessarily thriving. I don’t know a concrete answer to this, but I have a hunch. In any case, it’s interesting to contemplate.
The above is just my opinion piece with a dash of science to explain the process. Obviously, it is very complex and there are some wonderful more scientific explanations of it out there if you wish to better understand the concepts. For now, let’s dive into some myth-busting!
“I am in Ketosis”
When people come to me and tell me they follow a ketogenic diet, I listen, and then I ask my first question: Do you really follow a ketogenic diet? So many people aren’t truly following keto. Rather, they are merely reinventing the Atkins diet by following a strict low-carb approach. First lesson: Low carb does not = keto.
Other people consider themselves keto if they eat a lot of meat/protein. A true ketogenic diet is actually more about fat than protein. It is a high fat, moderate protein diet. This is crucial, as eating high protein can spike blood sugar in a similar way to excess carbs (super fascinating, and something many people do not realise). Ketogenesis is all about avoiding this blood sugar spike, so that instead of using glucose for fuel – remember, the bodies preferred method of energy production 😉 – the body utilises fat (with a by-product of ketone bodies).
Second lesson: it’s more about fat than protein. Protein actually slows down the process of ketosis. It is a moderate protein diet.
Even if individuals are focusing on fat, moderate protein and eliminating most carbs, many are not aware of the levels they need to consume/avoid to truly be in ketosis. Most are not measuring their beta hydroxybutyrate levels which would indicate whether they are or are not indeed in ketosis. It is approximately about 80% fat and 5-10% carbohydrates on a given day, which is incredibly hard to stick to. The rest is protein. To give you some more understandable numbers it is less than 40g net carbs per day (net = total carbs minus fibre. Because fiber is a carbohydrate that your body cannot digest, it does not spike blood sugar). As carbohydrates are in lots of foods, this could mean you only have 1 carb for the day, say, a banana, and you still have a little room for the small amount that comes with your other food like veg. Not much at all! Very hard to comply with.
Third lesson: Measure your ketones via urine strips to check you are actually in ketosis.
MYTH # 2
“The ketogenic diet is a suitable diet for long-term health”
There are no long-term studies showing a ketogenic diet is of benefit to longevity. There are no quality studies showing its usefulness in preventing or fighting cardiovascular disease or cancer events. Any small amounts of data that does exist, generally shows it helps relieve symptoms slightly, but it certainly isn’t preventative. This doesn’t mean it isn’t useful, it simply means the evidence is not there. Quality, human studies on ketosis in general are lacking. One way we can make a somewhat accurate judgment on this type of diet is if we look at the many studies that have been done on very low carbohydrate, high-animal based diets. Countless studies show us that indeed, with macronutrients ratios like this, particularly those based on animal-products (admittedly, probably higher protein than Keto), we do see a clear rise in risks related to cancer, CVD and early mortality. We also know for sure that a diet low in fibre, is associated with many digestive issues including diverticulitis and bowel cancer. Again, these studies aren’t specific to ketosis, but they are involving many of the foods that make up the bulk of keto diets.
There may be some instances where ketosis might have some positive outcomes i.e. in drug-resistant epilepsy (the exact mechanism of which is still unclear). However what has been observed in these situations is that it comes at a cost – mineral deficiencies, impaired bone metabolism, kidney stones etc. Note, you actually have to follow around 90% of fat and low protein/carb for this to be truly ketogenic and effective in this unique situation.
Heart disease – studies show that it can raise HDL (good) cholesterol and lower triglycerides. This seems alright, but LDL also goes up (known as bad cholesterol), even in spite of weight-loss which usually lowers LDL?! This is strange and not a good sign for long-term health.
Diabetes – ketosis seems to drop blood glucose levels (by not consuming/utilising glucose) but does not fix the underlying cause of the dysfunction nor does it reverse it. It is a band-aid because it is premised on not spiking blood sugar… but why can’t the body regulate blood sugar efficiently? Lipotoxicity (fat build-up inside of muscle, liver and pancreatic cells) is likely the culprit and has indeed shown to be a direct cause of type 2 diabetes. Therefore eating excess fat, as you do in Keto, is not working from a “root-up” “fix-the-problem” kind of place. Safe to say it exacerbates it, which people might not find until they come off it and reintroduce normal amounts of carbohydrates 🙁
Alzheimer’s – the theory behind this is Alzheimer’s is described as “insulin resistance localised in the brain”. Whereby brain cells don’t respond well to insulin, so glucose can’t enter the cells and deliver the fuel needed. Ketones as an alternative fuel source may therefore seem like a good idea… however again, like diabetes, high saturated fat is actually linked to the risk of getting the disease to begin with. Thus it is not a preventative diet. There has been some research showing a sub-group of Alzheimer’s patients with a particularly genetic predisposition that did respond well to ketosis in terms of cognitive function. However this was simply symptom improvement to a medication-induced ketosis, not food, and unfortunately, their disease progression stayed the same.
Cancer – Theoretically, people think it might help people in treatment i.e. those getting radiation or chemotherapy. There may be some potential here, but we do not have the data to be conclusive. Cancer patients are often at risk for malnutrition, nausea and constipation already, so ketogenic diets are not suitable until further research is done. As it’s vague promise has only been shown in treatment and not prevention, it is kind of as the above with diabetes and Alzheimer’s. You wouldn’t get chemotherapy to prevent cancer right? It’s just useful short-term, when you have the disease. Ketogenic diets might (not sure yet), be able to be used when cancer exists for short-term intervention to protect normal cells and make cancer cells more susceptible to treatment. Definitely more data needed, just pointing out that it is only really indicated in treatment not prevention!
“Ketogenic diets are effective for weight-loss”
People say this all the time. Studies have shown some short-term weight-loss. And many people trialling the diet rave about their fast results. But is this real weight-loss? And does it stay off?
People lose weight in ketosis for a few reasons:
1 – you lose water from the body initially when eating low-carb. This is for several reasons but mainly because carbohydrates are generally full of water and when you cut them out, you eat less water-filled foods. Secondly, glycogen (livers storage of carbs) becomes depleted with low-carb intake, therefore there is water loss. Finally, ketones encourage your kidneys to dump excess water and sodium, so you will urinate more frequently, particularly in the beginning.
2 – They have likely cut out a lot of processed and sugary foods in order to reach the very low-carb requirements. This is great! I like this part of the keto diet (really, part of any “diet”). This dramatic change to most people’s dietary choices can definitely have the effect of weight-loss.
3 – People who are sticking to a “diet” are likely to be in some sort of calorie deficit overall, this will always lead to weight-loss (particularly when an entire macronutrient is cut out).
4 – Fat is very satiating, so many keto or keto-ish dieters tend to eat less, again, leading to a calorie-deficit. Are they in ketosis? Not sure! But they are eating less so weight-loss is inevitable.
As there really are no long-term studies on ketogenic diets we don’t know how long the initial weight loss stays off. Shorter term studies and clinical experience has shown, that many people find it difficult to stick to. This is due to the unrealistic and strict ratios of a ketogenic diet, and, by my standards at least, unenjoyable way of eating. This suggests that the weight creeps back quickly. Sustainability is key when it comes to weight-loss and of course, overall health.
Something to note, when somebody chooses to have a “ketogenic meal” but isn’t really following a ketogenic diet overall, this can be detrimental to weight because if the rest of the day they are eating normal amounts or high amounts of carbohydrates, they just had a huge fatty meal, and high carb + high fat together is a recipe for disaster.
The Risks of Ketogenic Diets
- Digestive health – increase risk of colon cancer and other GIT dysfunction due to low fibre intake. Constipation and nausea have also been noted from a low-fibre, high-fat diet.
- Kidney health – Gluconeogenesis creates extra nitrogen then usual, which kidneys have to deal with/excrete.
- Impaired arterial function – low-carb diets tend to stiffen/clog arteries, impeding peripheral circulation and restricting blood-flow to the heart, leading to an increased risk of cardiovascular diseases.
- Overall mortality – lower carb diets are linked to greater chances of dying from all causes.
- Birth defects – if a woman is following a low-carb diet prior to falling pregnant this might present an issue, as it often takes several weeks before a woman knows she has conceived. Something to be very cautious with.
The moral of the story is that at this point in time, what we do know points to the fact that short term goals of weight-loss, appetite control and dewy skin can be achieved through a diet that doesn’t sacrifice your long-term health. You have to ask yourself if it is really worth the downsides/side effects mentioned above, when there are many other ways to lose weight and feel energetic that can coexist with long-term health objectives, and have the data to support it.