The Keto Diet
What the heck is keto? Why am I doing it for 90 days?
Keto is a very low carb, moderate protein, high fat diet. When you’re in ketosis, you’re using ketones for fuel instead of glucose from carbs. There are different types of ketogenic diets - listed below.
Standard keto diet (SKD): Very low carb, moderate protein, high fat. 75% fat, 20% protein, 5% carbs.
Cyclical keto diet (CKD): Involves periods of higher-carb refeeds, such as 5 keto days followed by 2 high-carb days.
Targeted keto diet (TKD): Allows you to add carbs around workouts.
High protein keto diet: Similar to SKD, but includes more protein. 60% fat, 35% protein, 5% carb.
The ketogenic diet has been around for a very long time and has been studied extensively. Cyclical & targeted keto are more advanced methods primarily used by bodybuilders or athletes. One of the biggest health benefits of keto is that it can be a tool for treating neurological disease such as epilepsy.
Foods that you’ll eat a lot of on a keto diet: meat, poultry, fish, seafood, eggs, avocado, coconut oil/milk, olive oil, nuts and nut butters, bacon, butter, cheese, leafy greens, asparagus, cucumber, celery, tomatoes, peppers, mushrooms, zucchini, & other low carb veggies.
This type of diet can be an easy for someone to stick to initially because of how full and satisfied you will be from eating lots of fat and protein. Keto when used properly is amazing, but I am not a fan of people using it as a fad diet.
In fact, a big reason people are seeing lots of initial success with it is because they’re going from a standard American diet (fast food, sugary coffee drinks, soda, lots of processed food) to now eating REAL food on keto & they’re just eating less food (calories) overall.. aka that they’re losing weight due to a caloric deficit rather than just because they’re doing keto.
The reason that keto isn’t sustainable long term for 99.9% of people is because of the extremely low amount of carbs. Now, I’m not saying you can’t be keto for your whole life. You totally can, but there will still probably be times where you want to eat some cake or have some ice cream or pizza & it’ll throw you out of ketosis.
Keto is a pretty safe thing to do if you’re a healthy person. I should have mentioned this in part 1, but keto was “created” to help people suffering with lneurodegenerative disorders, to get the health benefits of fasting without actually fasting aka brain health, clearer thinking, reduced anxiety, etc.
There might be side effects while your body adapts to keto though which is called “keto flu.” Some symptoms of this are:
-Poor energy & mental function
Keto flu is largely due to the fact that your body’s electrolyte balance is off, so taking some supplemental electrolytes can help. I didn’t personally experience keto flu, but I know there are many electrolyte tablets out there that you can take.
How does ketosis actually happen? (adopted from @precisionnutrition)
-Our body releases fatty aides from our stored body fat & enter other cells
-Fatty acids are combined with co-enzyme A to form acetyl-CoA chains
-These chains move into the mitochondria & are broken down into acetyl-CoA units by a sequence of reactions known as β-oxidation.
-“Chemical magic happens” & acetyl-CoA forms ketones: acetoacetate and β-hydroxybutyrate, along with acetone.
-Ketones are released by the liver into the blood
-Almost any cell that needs energy can grab it from these circulating ketones, & our brain will be the greediest for these molecules!
Ketosis happens when blood ketones are higher than normal either through dietary changes (which lead to very low blood glucose) or through supplementation (independent of blood glucose concentrations). “Some people like to think of ketone bodies as the fourth energy source for humans (in addition to carbohydrates, fats and proteins). That’s technically true, but the alcohol in booze (aka ethanol) can also be used for energy. Just because we can metabolize something doesn’t always mean we should.
Ketoacidosis is a dangerous situation of uncontrolled ketosis when our blood gets too acidic. Usually our bodies are good at compensating, but if not, this can happen. Diabetics and alcoholics are higher risk.
Ketosis is essentially an effect of fasting. That means that many of the health effects of fasting may be due to ketosis, rather than the act of fasting/energy restriction. After a certain amount of hours spend fasting/in starvation, ketogenesis happens and you’re in ketosis because you’re taking away the normal readily available energy source, glucose. When we stop eating, we run out of stored glucose (glycogen) within 2-3 days (faster if we’re active), and have to find some other fuel source (ketones). There are a few different ways to get into ketosis.
1. We make our own ketone bodies naturally through ketogenesis.
2. A keto diet
3. Ketone supplementation
Today, we can supplement with ketone bodies (exogenous ketones) and raise the level of ketone bodies in the blood without being in ketogenesis, therefore giving the health benefits without having to follow a keto diet or fast/starve. There isn’t much research or human trials that have been done on this, though.
Who might benefit from a keto diet? (adopted from @precisionnutrition)
Metabolic disease: research suggests that in some cases of type 2 diabetes, ketosis may be useful as a short-term treatment that helps return metabolic processes back to a more normal state.
Neurodegeneration and brain injuries: some of these diseases show common features like oxidative stress, mitochondrial dysfunction, and inflammation. Alzheimer’s is now often described as “diabetes of the brain”. The presence of ketones seems to improve outcomes from TBI and can be a low-risk treatment/strategy to improve brain health.
Is it healthy to be keto long term? It’s unclear. There haven’t been any studies or control groups with humans in the same lifestyle, environment, etc. to show that anything was solely related to being in ketosis. Therefore any longevity benefits would be speculative and anecdote.
SHOULD YOU DO KETO?
For the vast majority, probably not. Especially if you’re an athlete trying to increase your performance. “Ketosis lets you avoid glycogen depletion (aka bonking, hitting the wall), bc you aren’t using glycogen as your energy source, so you don’t need to take in carbs as you compete. Instead you’re using fat and ketone bodies. You increase fat oxidation, spare glycogen, produce less lactate and use less oxygen at submaximal rates.” (cc @precisionnutrition)
However, the exercise physiologists’ consensus is that while all these adaptations are true, the problem is that with fat and ketone bodies as fuel, you’re not going to go as fast as you can when using with glucose and carbohydrates.
One interesting thing though is that combining the two (60% dextrose, 40% ketone ((R)-hydroxybutyl (R) -3-hydroxybutyrate ketone ester).) might offer some benefit. They did a study with cyclists to drink half of their drink, ride for 1 hour at 75% of their max power output. Then they drank the other half of their drink & biked as far as they could in 30 minutes.and the results from drinking the carb + ketone drink showed an average 2% farther longer over the 30 minutes.
Sustainable/maintainable fat loss? Probably not. (for most people)
Gaining lean mass? Probably not. We need insulin along with other hormones to create an anabolic, muscle building environment. “Trying to build muscle while in ketosis is like stepping on the gas and brake at the same time.” What’s this mean?
Try keto if you want with proper guidance and education, but be aware that personal anecdote and actual science are not synonymous.
If you feel good while doing keto and think it’s sustainable for you and your lifestyle forever, great, do it. No one is stopping you. But that doesn’t mean that you should be telling people it’s the best thing out there. Your response to something is different than someone elses!