Before we dive into the deep end of the biochemistry of ketosis, a small disclaimer:
If you are currently on a ketogenic diet and ARE ENJOYING IT, this keto-focused blog series is in NO WAY meant to deter you from your progress. However, if you are confused about what a ketogenic diet is, or what ketosis is for that matter, and are wondering whether or not this pattern of eating is the only way to burn fat (lose weight), stay a while.
If you're reading this, chances are you're already somewhat familiar with at least a few of the following terms:
KETOSIS.
KETO.
KETOGENIC DIET.
KETONE BODIES.
KETO-SCHMEETO.
Okay I made that last one up. The point is, I see these words being tossed around haphazardly all over social media lately like they're the coolest words in the world and all I can think to myself is:
My friends didn't think these words were cool when I tried to share them from my biochem book in undergrad. Like, nobody gave a crap about beta oxidation of fatty acids circa 2010. "Yeah that's great, Lee Ann, you're right the body is awesome uhm can you plz turn up KUWTK? I really want to see what happens with Kim and that basketball player."
I know Scott. Me, too.
Moving on.
The point is that much of what you see today regarding the ketogenic diet is nothing more than a hyped-up-uber-glamorized version of information that's been around for 100 years, which is that when carbohydrates are lowered to a crazy low amount or run out completely, your body switches to fats as its primary fuel source. Therefore, ketogenic diets are often marketed as a method to "turn on your body's fat burning mechanisms to trick your body into burning more fat" (Side note: your body is so much smarter than you. You can't "trick" it. Don't believe that mess).
Before I continue with the principal of the ketogenic diet, I would like to bring back my biology textbook. It's 8 years later, and I'm going to get the chance again to make you think I'm cool. KUWTK isn't even on right now, so don't leave me. Point is, I want you to know 2 things:
1) Education is empowerment. I want you to take the information I am sharing with you and USE IT TO YOUR ADVANTAGE. Here's the thing about me-I'm trained to scrutinize information from ALL SIDES. Science is never about trying to prove your hypothesis (what you PREDICT is going to happen) right, it's all about trying to prove your prediction WRONG. Therefore, I use both evidence gathered by other scientists (that I pick apart) and myself through experimentation (that I pick apart) to come to an overall conclusion that is based on evidence and not overstated. No egos involved. The goal is to get closer to figuring out what's happening biologically so that we can improve our knowledge of particular subjects, which gets us closer to finding cures for diseases. It's okay (and GREAT) for you to question the things that relate to your health, just make sure your sources are credible so that you can trust where the answers to your questions are coming from.
2) You are intelligent. You are completely capable of understanding how your body works. It's just that often times it's either oversimplified to the point where accuracy and precision are completely lost, or alternatively it's over complicated to the point where no wonder you want nothing to do with science. My hope for these education based entries is that I can provide you with some happy medium.
Alright happy medium time. Let's go to keto-town.
What is ketosis?
"Ketosis is a metabolic state characterized by raised levels of ketone bodies in the body tissues, which is typically pathological in conditions such as diabetes, or may be the consequence of a diet that is very low in carbohydrates." -Merriam-Webster
Translated:
To keep you alive, your body needs to produce energy. Your body can produce energy by breaking down carbohydrates, fat, and protein that you get from food. Carbohydrates are your body's PREFERRED fuel source, and fat comes in second. Protein can also be turned into energy, but as long as you are consuming calories from fat and carbs, your body won't tap into this as an energy source. If your body has no carbs, it turns to fat as an energy source. Fat is broken down to produce ketone bodies, which is what provides the fuel for the body when you're out of carbs. If you stop eating carbs completely, you'll go into ketosis (because of all the fat breakdown) pretty quickly. This is why ketogenic diets try to reel you in by saying things like "unleash the power of your body's fat burning potential!" like it's some innovative, new wave crazy scienc-y magic that was recently discovered. Nope. Ketosis has been around forever. Marketing just makes it sound sexier (which is ironic, because if you chose to go keto, your breath is probably gonna STANK. You'll learn about that in part 3).
So, why does the body burn carbs before fat?
1) EASE OF BREAKDOWN: Fat molecules (tryglycerides) require more time to break down than carbohydrates. Carbohydrates from simple sugars (coca cola) are immediately available for energy production. This is why you experience a "sugar high" after eating a candy bar or drinking a soda. Carbohydrates that are more complex, like those that come from vegetables and grains, form long chains that we call polysaccharides (multiple sugars linked together). What's cool about these complex carbs is that they can still be broken down faster than fats, but in a time released fashion. This keeps your blood sugar from spiking really quickly. So, when it comes to speed, simple carbohydrates produce energy the fastest, followed by complex carbohydrates, followed by fats.
2) YOUR BRAIN LOVES CARBS. Your brain is VERY metabolically active. As such, it doesn't make sense that it would want to run off of a fuel source that takes longer to break down. It wants energy and it wants it NOW! LOL remember these commercials?
Think of this analogy: It's 5 p.m. and you haven't eaten all day. You're ravenous. At your home, you have a refrigerator in your kitchen, and a freezer in your basement. Both have your favorite meal in them, except the one in the basement is frozen. Does it make any sense for you to walk to your basement, grab a frozen meal, defrost it, and then eat it when you've already got that same meal upstairs ready to go? Nope. Your upstairs fridge represents carbs. Your basement freezer holds fat. Fat just takes longer to process.
Your body, being the incredibly smart machine that it is, is hardwired for survival. Carbohydrates are stored in your liver and muscles. Fully carb-stocked muscles and liver can provide about 24-48 hours of energy for your body. So what happens when that gets used up (i.e. you don't eat any carbohydrates for that period)? Your body turns to fat as a fuel source for survival, which can carry you for up to 3 weeks without any food. Water is a different story of course-days without water will kill you dead-but I digress.
Fat cannot gain access to your brain to be used as energy, so it gets processed in the liver first and turned into ketone bodies, which then move into the bloodstream and then get delivered to your brain for energy. So it's GREAT that your body is able to use different fuel sources for energy! If we functioned only off of carbohydrates, we'd only last a few days (MAYBE) without food before our brain shut off. Thanks to fat stores in our body, we can survive during times of food shortage.
So, just to recap: Your body uses carbs and fats and can use protein for fuel. Your body likes to use carbs first if they're around. If they aren't, your body starts to break down fat as fuel. Ketones are products of fat breakdown. Build up of ketones in the blood = ketosis. You will not be in ketosis if you have carbs in your bod.
Marinate on this, and we'll continue this journey tomorrow night. If any questions regarding this information start to pop up, feel free to post them below! Burke (the other half of JB who is always behind the camera) and I love hearing from you. Don't be a stranger! We're all ears. See you tomorrow, friend.
-Lee Ann