Carbohydrates Basics: What they are,and what they do in the body

Carbohydrates Basics: What they are,and what they do in the body

It’s important to learn the basics of food chemistry. It is empowering to bring this awareness into light, however, I realize that it can be a tad overwhelming so my hopes are to provide you with the basics in a simple to understand way.

The basics

  1. Carbohydrates are actually built of sugar molecules, called saccharides which are further broken down into 3 main groups – monosaccarides, disaccarides and polysaccarides.
  2. Basically everything ending in “ose” is a sugar.
  3. A sugar chemical makeup consists of carbon, hydrogen, and oxygen. Their configuration and amounts of each will differ slightly depending on the type.

Monosaccharides are simple sugars. They include glucose, galactose, and fructose. The primary difference between these are how your body will metabolizes them.

  • Glucose is the most basic form of sugar and is required by all cells in the body for energy even the brain and red blood cells. Glucose is the only form in which sugar can be transported directly into the bloodstream.
  • Galactose is that sugar that is found in lactose or milk. The chemical structures of glucose and galactose are very very similar yet because of this slight structural difference galactose will need to go to the liver – not the directly into the bloodstream like glucose – where it will be converted into glucose. This adds more work plus enzymes and nutrients – for the body.
  • Fructose is a fruit sugar. Again the chemical make up is different and therefore the body – digestive system – will need to treat and absorb it differently. Similar to galactose, fructose will need to travel to the liver where it will be converted into glucose and then used by our body’s cells.

Disaccharides are double sugars in which 2 monosaccarides are bound together. This is what we normally find in our foods.

  • Sucrose, table sugar, is the meeting of glucose and fructose.
  • Lactose is the joining of glucose and galactose.
  • Maltose is the joining of 2 glucoses.


Polysaccharides are mostly our plant and our complex carbohydrates sugars as they are chains of many many monosaccarides.

The two classifications of carbohydrates

Basically the classification depends on the chemical structure of the carbohydrate food and how quickly it is digested and absorbed in the body. The more nutrients and fiber in the food, the more likely it will be a complex carbohydrate ( and better for you!).


Simple carbohydrates are broken down quickly in the body. Some simple carbohydrates – like fruits, milks – have beneficial nutrients in them; however, others like processed and refined sugars – store bought baked goods, candy, table sugar, syrups, and soft drinks – are void of any nutrients (vitamins, minerals and fiber) and actually create more work for the body to digest it. And this creates a very large problem in the health of the body.

A sugar fact: In general, the sweeter a sugar is the simpler it is.

Complex carbohydrate

Complex carbohydrates are chains of 3 or more single sugar molecules and are called our polysaccharides. Cellulose, another type of complex carbohydrate, is the main component of fiber (fiber slows the digestion and absorption of sugar – a great thing) and gives structure to plants.

Foods: Think color and whole grain. Broccoli, legumes, whole wheat, leafy greens.

Why carbohydrates are important

Many people think carbohydrates are not needed in the body but in fact, if eaten in moderation – complex carbs that is – are extremely important.

  1. The primary function of carbohydrates is to provide energy for the body
  2. Amylase is the main enzyme to help break carbohydrates down into glucose
  3. Your body prefers to use glucose as the main source of fuel for daily activity
  4. Your muscles need glucose to move and your organs need glucose to function, including your brain

The key is to eat the right type of carbohydrate which we will talk about in later posts.

Be well


Heather Manley N.D.

Dr. Heather Manley, who in 2001 received her medical degree from the National College of Naturopathic Medicine in Portland, Oregon, is a practicing physician whose primary interest is preventative healthcare for families.

Note: This Perspectives Blog post is written by a guest blogger of The opinions expressed on this post do not necessarily reflect the opinions of Dr. Greene or, and as such we are not responsible for the accuracy of the information supplied. View the license for this post.

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