Carbohydrates have gotten a lot of bad publicity through the years. Before we toss them out of our diet completely it’s important to know what they are and understand the vital role they play in our bodies.
I’m going to try to keep it as simple and cohesive as I can.
Carbohydrates are one of the three primary macronutrients in our diet, including fat and protein. They are called Macronutrients because they are needed in large quantities. All carbohydrate molecules contain carbon, hydrogen, and oxygen atoms in specific ratios. Thus, in the nutrition and chemistry world carbohydrates are often referred to as CHO.
The most basic fundamental unit of a carbohydrate is a monosaccharide (“one” sugar). Monosaccharide examples are glucose, galactose, and fructose. These along with disaccharides (“two” sugars) are considered simple carbohydrates. Oligosaccharides or polysaccharides (“three or more” sugars) are considered complex carbohydrates.
The primary role of carbohydrates in the body are to provide energy, store energy, and spare protein and fat for other uses. Carbohydrates also facilitate blood glucose and insulin metabolism, promote good digestive health, lower cholesterol, and lower your risk for other health issues such as heart disease and diabetes.
Digestion, Absorption, Energy, and Storage
Upon food consumption, the digestive tract begins to break down carbohydrates into glucose, which then enters your intestines where it’s absorbed. From there, it passes into your bloodstream. The glucose in your blood stream is used for immediate energy and the extra is turned into glycogen and stored in your muscle and liver cells.
Your body is designed to keep a homeostatic (balanced) state at all times. It’s quite awesome actually!
When you eat food, beta cells in your pancreas monitor your blood glucose levels. When your blood glucose rises upon eating, the beta cells release insulin into your blood stream. Think of insulin as a key- it unlocks muscle, fat, and liver cells so glucose can get inside. After your body has the energy it needs, the leftover glucose is stored as glycogen in your muscle and liver cells to use when energy is needed again.
When you haven’t eaten for a few hours, your blood glucose level drops. Your pancreas stops pumping out insulin. Alpha cells in the pancreas begin to produce a different hormone called glucagon. Glucagon signals the liver to breakdown stored glycogen and turn it back into glucose- and "boom" you have energy back!
Most of the cells in your body use glucose, along with amino acids (building blocks of protein) and fats for energy. If glucose is present, it will be the main source of fuel for your brain and body. In the absence of glucose, energy can be made from either the breakdown of protein (generally from your muscle tissue-not good) or the breakdown of fatty acids in the form of ketone bodies. This can happen overnight, during dieting, and/or times of fasting.
There are three types of carbohydrates we consume: starch, sugar, and fiber. These carbohydrates are also known as simple and complex carbohydrates.