Nutrition #8 - Nutritient Biochemistry for Dummies - Carbohydrate Primer

This blog post will explore the basics of nutrient metabolism, and the different macronutrients and micronutrients necessary to sustain life.

First of all, see this chart?

Throw this out the window. 'Whole grains' are NOT as good for you as we've all been raised to believe, and I am hopefully going to help you understand why. The food pyramid was created by our glorious agriculture companies in order to create a massive market for these huge crops like corn, wheat, barley, rye, and other grains in America. 

Macronutrients

Macronutrients are the primary building blocks in food. The three primary macronutrients are carbohydrate, protein, and fat. Alcohol is also technically a macronutrient, but is much less common in our food sources, and is a fermentation of carbohydrate. Each macronutrient plays many different roles and provides a variety of functions in the body. They are required in varying quantities based on your activity levels, your lifestyle, whether you are male or female, how much and how well you slept, your circadian rhythm, your climate, your environment, your exposure to stress, your hormone levels.... Basically everything will influence how much or how little you will need in these three quantities in order to function optimally. I am not going to explain exactly how much for each little nuance as that will take days of tinkering, calculation, and bloodwork, but I can help you understand how to get on the right track.

What is a carbohydrate?

A carbohydrate is a chain of glucose molecules, which are simple sugars. Simple sugars (glucose) are the primarily source of fuel for every cell in the body. Glucose can be metabolized for energy by the cellular powerplant called the mitochondria. Now, glucose can be stored in the body for use at a later time as glycogen, which is the storage form of this molecule.
The natural cycle of the carbohydrate: carbohydrate is the long-chain storage form for glucose in plants such as legumes, tubers, and fruits, which is then broken down in the body into glucose, which is then either readily used as fuel or stored as glycogen in our muscle cells or liver.

Simple carbs vs. Complex carbs
Carbohydrates come in two types that we have all heard - 'simple carbs' or 'complex carbs'. Simple carbs refer to very short-chain glucose combinations, monosaccharides and disaccharides. A monosaccharide is just one sugar molecule while a disaccharide is a combination of a sugar and glucose. Other monosaccharides include fructose, which is the primary simple sugar in fruit, and galactose, which is found in dairy. A great example of a disaccharide would be sucrose, which is common table sugar - a glucose molecule and fructose molecule bound together. When simple carbs are consumed, because they are already broken down to their core components they are readily absored into the bloodstream, causing a rapid spike in blood sugar. A rapid spike in blood sugar will cause an insulin response, which we will talk about later. Basically, it is not good unless strategically used to refill muscle glycogen stores.

Complex carbs, on the other hand, are polysaccharides, meaning long-chain glucose molecules. Polysaccharides examples include cellulose and starch, which is what we hear about most often. These chains can be tens or even hundred of glucose molecules long, and our bodies have to break down this chain via hydrolysis - the cleavage of a chemical bond by adding water. (Have you ever gotten very thirsty after a huge carb binge? This might explain that. ) From there, we can metabolize the glucose molecules individually and send them off where they need to go. These complex carbs, due to their structure and the work required to absorb them, cause a much more gradual rise in blood sugar as our body slowly metabolizes the glucose from the chain. More gradual rise in blood sugar = less of an insulin response = less storage of fat. More on that to come.


The Glycemic Index
The Glycemic Index score, or GI score, is a scale used to determine how much of an effect a particular food has on your blood sugar. On a scale of 0 to 100, it ranks foods on the increase in blood sugar for consuming 50 grams of carbohydrate from that food source versus 50 grams of pure glucose (which would cause the biggest increase).

See below chart:

Just a side-note, the GI impact of food will also be altered based on what else you ate with it, hydration, and other variables. The biggest thing that will reduce the immediate rise of blood sugar is fat consumption alongside the carbohydrates. Now, I am not recommending you go out and slather your pancakes with butter, this is just to explain why you see something like a snickers bar having a lower GI than a peach.

Which type of carbohydrates should I eat?

Carbohydrate consumption is something that varies by the individual. One of the biggest things I recommend is that we cut out all nutrient devoid carb sources of any kind. From there we want to focus on eating carbohydrates sourced primarily from plants - starchy vegetables and some fruits. These types of carbs will generally have lower GI impact, and are accompanied by fiber, vitamins, minerals, and other nutrients. One thing we want to always look at when choosing food sources is the relative nutrient density of that particular food. This will keep you from feeling hungry, tired, low energy, or having cravings, among other things. Oftentimes we eat a meal then feel like something is "missing", or we feel unsatisfied by that meal. This could be a sign you are missing a particular vitamin, mineral, or other micronutrient and your body is telling you to keep eating until you fill that gap.

So choose carbohydrates that come from whole food sources, as unprocessed as possible. If you fully eliminate the carbs from processed sources, things like wheat and dairy, and you're consuming no-sugar added beverages or sweetened drinks (water, unsweetened tea, etc), it is likely you will have a much more reasonable carbohydrate intake without even tracking any your consumption.

The problem is most people have grown accustomed to having carbohydrates for breakfast, lunch, dinner and snacks. Wheat and/ or dairy products are the staple of every family's kitchen. Cereal or toast with breakfast, a sandwich at lunch, pasta with dinner, and crackers or chips for a snack. Right there we have succeeded in spiking our blood sugar and releasing insulin (remember - this is a fat storage hormone) multiple times through the day, and we are riding a roller coaster of ups and downs of energy from the peaks and troughs of the blood sugar levels through the day. At the same time, we are not really getting much relative nutrition in terms of micronutrients per calorie.Combine all this with the fact that gluten (the protein found) in wheat actually impacts the brain in the same way heroin does (here is one study that talks about this), we have uncontrollable cravings that lead to overeating, lack of satiation, binge eating and even negative hormonal effects, among other negative impacts.

Talk about a problem! These are are all standard issues with the modern American diet.... and will continue to be as long as agriculture companies continue to monopolize the food market and be responsible for creating things like the food pyramid. And here we are, led to believe our whole lives that "whole grains" are good for you and to consume 8+ servings a day. This is ridiculous. I'll do a post later on, about the detrimental effects from gluten, but for now the general consensus and recommendation is to stay away from it and replace these types of foods with actual food, not 'frankenfoods' or a GMO (genetically modified organism) crops such as wheat. Cereal grains (wheat, rye, barley, etc) tend to have high toxin load due to storage/ shipping after harvest. Reduce this by eating foods that you could theoretically remove from the ground and consume, and you will begin to feel much better. Who ever heard of bagels growing on trees?

When should I eat carbohydrates?

As I mentioned earlier, the problem we see very often is that people consume some form of carbohydrate with nearly every meal, causing insulin response and fat storage. By turning off this response through limiting carbohydrates to specific meals at specific times, and consuming the right kind of carbs, we spend more of our waking day in a state of lipolysis, or the break down of fat for energy. This is our natural state in the absence of circulating blood sugar - we need to get energy from somewhere! While we do release some from energy from our liver, based on the stored glycogen there, we are also breaking down adipose (fat) tissue in the absence of carbs.

Where I am going with this - be selective in your carb consumption. I recommend spending as much of the day in a low insulin state as possible. I also recommend exercising in this low insulin state to better break down and mobilize fat for energy. Studies have shown low insulin during workouts can actually improve MPS (muscle protein synthesis). Combine that with the increase in fat burning you get while resistance training or exercising in general, and you are on the road to getting lean.

So eat your carbs either after your workout when you are in an insulin sensitive state, or with your last meal of the day. I usually eat all my carbs with my last meal of the day, and it comes out to around 100 grams a day of total carbohydrate consumption. I stick with sweet potatoes usually but also consume carrots, beets, butternut squash, and berries regularly. All these foods are great carbohydrate choices, and when you eat them with the last meal of the day you will experience an improvement in your sleep quality. This is because these types of carbs will stimulate serotonin production in the gut, a hormone responsible for creating melatonin.

Last Words

There you have it - that is a breakdown of some basic carbohydrate biochemistry, and the basic mechanisms behind how they play a role in either fat storage or fat burning. Hopefully I helped someone understand a bit more on what they do. I will do additional blog posts on the biochemistry behind protein and fat in future episodes. For now, choose the right carbs to eat at the right times and watch your body fat regulate itself to more natural levels. It really is that simple. Good luck on your journey to health.