Biochemistry Primer

[bjjcaveman]

- Here's a write up I've been working on -

When I tried to explain nutritional ketosis to my family recently I was met with a lot of blank and confused looks. I incorrectly assumed that my family knew as much as I did regarding regarding nutrition, biochemistry, and physiology and forgot that no one else in my family has a science background (I have a degree in physiology and work in healthcare).

To understand how nutritional ketosis works you have to understand a little bit of biochemistry. So I wanted to type up something that my family and anyone else who doesn’t have a science background can refer to.

Here are a few basic topics that I think will help someone have a better understanding of nutritional ketosis (and any other diet). I know this is extremely simplified and is extremely NOT comprehensive, but it’s as good a place to start as any. I hope you find this helpful.

The BJJ Caveman’s Primer on Basic Biochemistry

Macronutrients

Carbohydrates

• Carbohydrates that you eat are combinations of sugar molecules
• Glucose is the most common type of sugar molecule
• Your body digests carbohydrates by breaking them down into their component sugar molecules
• These are then absorbed into your blood stream.
• This causes a spike in your blood glucose levels.
• Insulin is a hormone released by your body when your blood sugar spikes to bring your blood sugar back into the normal range.
• The glucose in your bloodstream is first used for any immediate energy needs and any left over is converted for storage.
• Your body stores excess glucose as glycogen, which is basically a long chain of glucose molecules, to be used for energy later.
• If too many carbohydrates are consumed, to the point where your glycogen stores are completely filled, your body converts these carbs into fat.

Fats

• Fats that you eat are in the form of triglycerides, molecules consisting of three fatty acid chains and a glycerol molecule.
• After a fatty meal, your body absorbs triglycerides into your blood stream.
• Your body then uses these triglycerides for immediate energy or storage.
• When used for energy, triglycerides need to be broken down into fatty acids before being metabolized directly for energy.
• In situations when your body’s carbohydrate stores are depleted (as in fasting), fatty acids are broken down by the liver into ketones
• Ketones can then be used for energy by the rest of your body instead of glucose.
• When excess fats are consumed, they are stored within your fat cells.
• There is no limit to how much fat you can store in your body

Protein

• Proteins that you eat are made up of combinations of amino acids.
• Your body digests proteins by breaking them down into amino acids that are then absorbed into your blood stream.
• These amino acids can then be used directly for energy or as building blocks to make essential proteins that your body needs to function (enzymes, replenishing broken down muscle, etc.)
• When excess proteins are consumed, your body converts these additional amino acids into fat.

A key point to remember is that your body is very efficient in storing energy. It has the ability to convert any excess carbohydrates, proteins, or fats that are consumed into stored body fat.

The Importance of Blood Glucose

• Your body uses glucose for energy and needs a constant source of it to stay alive.
• Your body likes a blood glucose concentration of 70-100 mg/dl and it will do whatever it takes to keep the concentration in that range.
• If there is too much glucose, such as after eating a bag of candy, and your blood glucose gets too high,

• Your body will release insulin to bring the glucose concentration back down into the preferred range.
• If there is too little glucose, like after a fast, and your blood glucose is too low:

• Your body will break down any stored glycogen to make more glucose, bringing your blood glucose back into the normal range.
• If you run out of glycogen, your body will then find ways to make more glucose via a process called gluconeogenesis, by which your body converts other molecules into glucose.
• The primary source of this is through the conversion of amino acids into glucose (either from ingested protein OR from the break down of proteins already in your body)
• Your body can also convert lactate (a break down product of glucose metabolism) and glycerol (a break down product of fat metabolism) into glucose

Calories

• Calories are a measure of energy
• Carbohydrates, proteins, and fats all store energy
• 1 gm of carbs = 4 calories
• 1 gm of protein = 4 calories
• 1 gm of fat = 9 calories
• Your body requires a minimum amount of energy per day to function. This is called the ‘basal metabolic rate.’
• This does not include the amount of energy needed to do anything else such as digest food, stand up, sit down, brush your teeth, walk to work, etc.
• My estimated basal metabolic rate is 1700 calories.
• This is calculated from a mathematical formula.
• When you do any additional activity, your body uses more energy.
  For example, running a mile = 100 calories

Ketones

• Ketones are a breakdown product of fat that are only released in a low carbohydrate environment when there isn’t enough glucose
• Ketones can be used as an alternative source of energy by almost all of your cells when there isn’t enough glucose around.
• Ketones are actually a cleaner source of energy for your body than glucose.
• When ketones are used for energy, they release less free radicals (toxins) compared to when glucose is used for energy.
• An analogy would be: “ketones are to glucose what wind energy is to coal”

I'll post a primer on nutritional ketosis too.

Again, I hope you find this helpful. I know this is very simplified, but I had to strike a balance between oversimplification and accuracy/completeness.

[drjlocarb]

Good job!

Here is a post I did years ago along this same line of thought with a bit more about keto sticks. Just more info to add to your thoughts.

ABOUT KETONES-BIOCHEM 101

[Just Beachy]

Thank you both for your primers. I will admit that I am not a science person, so anything that makes it a little easier for me to understand and explain helps a lot.

I read once a post by darkginger on these boards that helped me a lot. I have used it as a jumping off point in how I now visualize the whole process. I will share how I now visualize it all. My science may be off a bit. If it is, please let me know and I'll try to come up with something more accurate. Anyway, first the post that got me started....

Originally Posted by Darkginger

Also be aware that not every source of carbs is equal - our aim is to even out spikes in blood sugar levels (and consequent insulin production). If you eat something which is easily converted to glucose ( forgive me if I'm at all off here, am not a professional, this is just how I understand it!) like, say, a cupcake (or corn, nectarine etc!) - then it gets rapidly converted into glucose, your blood sugar goes whoom, insulin floods out, and rushes the sugars off to your fat cells for storage.

What we need to be eating is stuff that tiptoes past the insulin secretors so they stay quiet and don't start marching up and down our blood vessels. I think of them as stealth foods, and imagine them creeping, ninja-fashion, past my dozing insulin. So yes, we eat carbs that lurk in green leafy veggies, but we shun the flamboyant sugars that do a Mardi Gras parade through our veins, which makes the insulin come out and dance.

I'm not sure that was terribly helpful, or even rational, but anyway, it's how I visualise it all

I love this post. I have come to think of insulin as guard dogs in a way. If the foods come barreling through (like in a Mardi Gras parade), it awakens the dogs and they come running and barking. The scared glucose goes running for cover and ducks into the adipose tissue of the body (fat cells). They never make it to their final destination and never get to feed the cells they were supposed to feed, so the body is still hungry. So, we want to eat food that will allow the dogs to continue sleeping.

Protein comes in quietly and goes where it needs to go. However, when we get to much protein some of it has to hang out in the bloodstream (hall) until it can go into the muscles. As more protein hangs out in the halls, they start to act like glucose and get louder and louder -- eventually waking up the insulin dogs. So, we need to eat enough protein to power our muscles but not so much that we leave it hanging out in the hall.

Meanwhile, the glucose that was chased into the fat cells cling to each other. Now, they are actually too big to fit back through the door of the fat cell. The only way they will be able to get back through is to relax enough to let go of each other and come out to see if the dogs are still there. To do that, they have to go quite awhile without hearing the dogs barking and chasing other glucose. Once the dogs are allowed to sleep for awhile. The do let go of each other and start to come out of their shelter and eventually make their way to the cells they were supposed to be fueling.

So, some of us have insulin dogs that sleep a bit sounder and don't wake up for every little bit of carb that comes through the bloodstream. That's why some people can eat more carbs and not gain weight. Others of us have dogs that are very light sleepers and wake up at almost any noise coming through the bloodstream (hall). Also, it is not unusual for the dogs to start out as heavy sleepers and become light sleepers as we age which is why the low fat diet that worked in our younger years doesn't work now.

Anyway, that is how I have been visualizing this whole process. I'm sure the science may not be exactly right, but I hope it is fairly close. Please feel free to add or correct anything to it. I'd love to be able to accurately explain how this works using a visual like this. I'd love to add in triglycerides and everything else, too, but I'm afraid that is beyond my understanding at this point. For us non-science types, something like this does help us understand things better.

Beachy

[Punkin]

Excellent analogy beachy. My dogs are very light sleepers, that is why I'm here. Seems like even one protein molecule that hangs out in the hall, wakes them up. It is so frustrating!