Nutrition focus is almost always shifting. From fats are the worst (hello 1980’s) to fats are the best! (a current swing in the dialogue). When we demonize one macronutrient, we glorify another. Currently, it seems like the trend in ‘popular nutrition’ is tending toward low carb and higher healthy fats and moderate protein. I can’t say I’m upset about this trend, because it’s great to see healthy fats on the table again! But, the downside to that trend is that we are collectively avoiding carbohydrates! With that being said, I believe carbohydrates are the one macronutrient that fall into the extreme more often than the other two- folks tend to go REALLY high carbohydrate or REALLY low carbohydrate. We cannot totally hate on one macronutrient- all three are important to balance a healthy lifestyle!
That’s why today, I’m sharing the first macronutrient-focused post in my The Basics series, Carbohydrates 101. Some points on the agenda for today include: what are carbohydrates? How do our bodies use carbs? How do we digest carbs? How many carbohydrates do I need? Then, in part two we will talk about some dysfunctions with carbohydrate usage and storage, and what that might mean for your health and I’ll give you some great examples of whole food carbohydrates to include in your diet. Let’s get going!
What are Carbohydrates?
Simply speaking, carbohydrates are the sugars, starches, and fibers found in food. Carbohydrates are made up of hydrogen, oxygen, and carbon atoms. They are also known as saccharides (which translate to ‘sugar’) and are categorized into four groups: monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Each type is based off of how many molecules make up each saccharide. Monosaccharides and disaccharides are digested very quickly because their simple structure is easy to break down, while oligo and polysaccharides digest more slowly because they are more complex.
How are Carbohydrates used in our body?
Unless taught differently (I’m looking at you, Keto fans!), carbs are our body’s preferred fuel source. Carbs tend to be a quick and easy burn, creating nearly immediate energy for our brain, muscles, cells, etc. Each gram of carbohydrate is approximately 4 calories of useable energy for our bodies.
Your body on carbs:
Brain: Our brain uses about 120g glucose per day and prefers carbohydrates, as they easily convert to glucose!
Muscle: Our muscles use carbs as fuel, but can also convert ketone and fatty acid bodies into fuel for use. Excess carbohydrates are stored in our muscles as glycogen. Generally speaking, we can store up to 1200 calories worth of carbs in our muscles!
Fat Cells: If our 1200cal of storage is full, we store excess carbohydrates (known as triglycerides) in our fat cells (adipose tissue) for use later. This storage was used primarily for preventing starvation during famine times, now; we have an overabundance of easily accessible food and rarely need to worry about famine conditions!
Kidneys: Your kidneys are very busy little organs! They are responsible for removing waste (as urine) and reabsorbing what we can use again, like sodium, minerals, etc. This constant filtering requires a lot of energy!
Liver: Our liver uses glucose constantly to fuel its metabolic functions. Our liver produces proteins that are vital for blood clotting, breaks down old and damaged blood cells, breaks down fats for metabolism, and is continuously secreting bile for proper digestion!
Additionally, a discussion on how our bodies use carbohydrates would be incomplete without talking about insulin, glycogen, and gluconeogenesis, and a few other “G” terms. In the simplest terms, I’d like you to understand these important components:
Insulin: our storage hormone! Insulin is created in the pancreas when there is too much sugar in our bloodstream from an intake of carbohydrates that is too high for our current needs. Insulin wants our blood sugar to stay level, and if our muscles and organs cannot immediately use ingested carbs, insulin tells our body to store the extra for later needs.
Glucagon: our release hormone! Glucagon is the opposite of insulin, it is also created in the pancreas and senses when there is too little glucose in our blood stream. Glucagon tells our liver to release stored carbohydrates and convert them into glucose to bring our blood glucose level back to normal.
Think of insulin and glucagon like the thermostat in your home. If you have the thermostat set at 75 degrees, it will work to stay there. When the temperature dips below 75, the heat will kick on. If the temperature rises above 75, your air conditioner will engage. Always keeping your home at 75. Our blood sugar balance works much in the same way. If there is too much sugar in our bloodstream, insulin will tell your body to store the excess glucose. If there is too little, glucagon will tell the liver to release stored carbs to raise the blood sugar levels. Keeping homeostasis, or keeping balance, is critical for proper body functioning.
Glycogen: the storage form of carbohydrates.
Gluconeogenesis: the act of making glucose from alternative sources (i.e. not carbohydrate sources) such as proteins and fats (amino acids and fatty acids).
Glycogenolysis: the breakdown of glycogen in the muscles and liver tissues as directed by insulin or glucagon.
Glycogenesis: the making of glycogen.
Was that too scienc-y for you? I hope not! It’ll get a little better from here :)
Digestion of Carbohydrates
The digestion of carbohydrates begins in our mouth, with the amylase enzyme. This enzyme is specifically in charge of breaking down carbohydrates, and then follows a roller coaster of stomach acid and chyme in our stomach and digestive enzymes in the small intestine to break down the carbohydrates into their simplest form, monosaccharides. Once they are in this form, they can be absorbed and utilized. Ultimately, glucose will head to the liver to be utilized or stored. Any carbohydrates that are not yet absorbed, will flow through to the large intestine and colon. Fiber from our food cannot be absorbed or digested, and contributes to our stool, helping remove waste products from our body.
How many carbohydrates do we need?
Trick question, technically none! Our bodies love using carbs because they are so easy to break down and such a quick source of energy, however, we can create glucose from amino acids and fatty acids if we need to! The amount that you will function best with depends on a lot of factors such as: age, genetics, lifestyle, activity level, injuries/illnesses, and your body’s ability to break down and utilize carbs. We can look at your specific needs in an initial intake based off of your goals and functioning!
I think that’s enough for one day and one post! I hope you found this entry enlightening and understandable. I know we got a little scienc-y for a few minutes there, but I promise you’re a better person for knowing more! You can never be overdressed or overeducated!
In Carbohydrates 101 Part 2 we will look at dysfunctions with carbohydrate usage and storage, types of carbohydrates, and examples of good, whole food carbohydrates to incorporate into your diet!
Are there any other topics you’d like to see me cover in Carbs 101 Part 2?