Carbohydrates are everywhere
Some of my following blog posts are going to deal with low carb, glycemic index, intermittent fasting, and ketosis. Therefore, I want to make sure, you know some essentials about carbohydrates.
Carbohydrates are the most important macronutrient for most people’s diets because they commonly make up the largest portion of our daily caloric intake. In contrast to proteins and fats, carbs are not essential. This means that our body can manage without carbs.
Why do we need carbs?
Their main function in our body is to serve as an energy source for our tissues. They supply our body with energy for keeping all body organs working such as our heart pumping, brain functioning, and lungs breathing. Furthermore, with their aid, we can follow our daily activities such as walking, cleaning, cooking, or doing sports. We can separate carbohydrates into two groups: simple carbohydrates (mono- and disaccharides) and complex carbohydrates (polysaccharides).
Mono- and Disaccharides
Simple carbohydrates are often called „sugars“ and can be split into mono- and disaccharides. Monosaccharides are glucose, fructose (fruit sugar), and galactose. Glucose and fructose are can be found e.g. in fruits. Galactose can only be found as a part of lactose.
Disaccharides are maltose, sucrose, and lactose. Maltose is composed of two molecules of glucose and is a product of starch digestion. It can be barely found in a normal diet. Sucrose is composed of a molecule of glucose linked to fructose and also known as table sugar. It can be found in many foods naturally. Lactose is composed of glucose linked to galactose and is also known as milk sugar. It is only present in dairy products. All these mono- and disaccharides are part of our diet with the exception of galactose.
All monosaccharides can be directly and rapidly absorbed into our bloodstream without complex digestion. Therefore, they are not as satisfying as complex carbohydrates can be. In contrast, disaccharides must be broken down into their two molecules of monosaccharides. We call this process digestion or to be more specific: hydrolysis. So, we are able to make use of the energy of the disaccharides by breaking them down to their monosaccharides to be able to absorb them into our bloodstream.
Complex carbohydrates are also called polysaccharides which are glycogen, starches and fibers. Glycogen can be found in meat in traces. Starches are polymers of glucose. If the glucose is linked together in a linear chain, you call this polymer amylose. If the glucose is linked together in a branched-chain, it is called amylopectin. Amylopectin and amylose, both form starch. Depending on your type of food, the type of starch can vary. There are quite endless formations of amylopectin and amylose possible: rice, fruits, bread… But, in the end, they are digested as their main component: glucose.
Dietary fiber is a non-digestible carbohydrate. This means that this type of carbohydrate cannot be broken down by our digestive enzymes and will get into our colon mostly intact. There, it may be digested by bacteria. There are several benefits of eating a lot of fiber: It supports the proper function of our gastrointestinal tract and prevents constipation and colon cancer. Animal products contain little to no fiber. Plant foods contain naturally substantial amounts of fiber. Complex carbohydrates take longer to digest and make you feel satisfied for longer. Read more about fiber in this blog post.
What happens to the carbohydrates after being absorbed into our bloodstream?
After a meal your blood glucose level goes up. This increased level of blood glucose is a sign of your pancreas to release a hormone named insulin. Insulin has several functions but the two most important ones are stimulation of the uptake of glucose into our tissues and stimulation of the conversion of glucose into glycogen. Glycogen is the storage form of glucose in the liver and our muscles. Therefore, our muscles have direct and fast access to energy sources. Sprinters know what I mean. 🙂 Our body is able to store about 500 grams of carbohydrates in our liver and muscles.
As a consequence, our blood glucose levels go down. This low blood glucose level triggers our pancreas to produce another hormone called glucagon. Glucagon and insulin are opponents and do exactly the opposite. Therefore, glucagon promotes the breakdown of glycogen into glucose. The consequence is a stable blood sugar level while fasting due to stored glycogen in our liver. Our body and several body functions can only work with enough glucose. Glycogen stored in our muscles provides energy for the specific muscle in action.
But what if our stores in the liver and muscles are full and we consume more carbohydrates?
Having full capacities in the liver and muscles, our body is able to convert glucose into fat. The consequence is as simple as it sounds: If you eat too much sugar, you can become obese very easily. When talking about blood sugar, we focus on glucose in our blood.
An important concern considering sugar consumption is the added sugar in many foods. This sugar is often linked to empty calorie foods. Empty calorie foods are often highly processed foods and rich in calories (energy) but lacking other important nutrients such as antioxidants or fiber. That’s the problem: You get a lot of calories and carbohydrates, you actually do not need. As a consequence of the full liver and muscles, your body produces bad abdominal fat.
Nevertheless, good carbohydrates are an essential energy source for our bodies. Based on this knowledge, I’m going to provide you some science- and evidence-based information about low-carb diets, ketosis, glycemic index, and intermittent fasting, soon. Feel free to share it and stay tuned on my Facebook-Fan page as well!