10 Jul Carbohydrates 101
One of the biggest struggles when trying to optimize one’s lifestyle is transforming nutritional habits. By far, the most common questions I get as a coach and friend are related to food composition, the what of nutrition. What are good proteins? Fats? What is fibre? What are good carbs? Today, I want to focus on what carbohydrates are and define the many shapes and colours they come in.
What are carbohydrates?
Carbohydrates are made of carbon, hydrogen and oxygen. Starches and sugars found in grains, vegetables, fruits and legumes are considered the main forms of carbohydrate and represent a significant source of fuel for the human body. Dietary fibre is also included as a form of carbohydrate; however, it does not actually provide fuel/energy making it a unique form of carbohydrate with a very important function in the body. Carbohydrates can be found in other foods including meat and dairy, but the amount of carbohydrate is very low.
How do they work?
Our body converts the majority of the carbohydrate we eat into a well known molecule called glucose. Glucose is one of the simplest forms of carbohydrates and finds itself in a group/class of carbohydrates known as monosaccharides. Mono meaning “one or single” and saccharide referring to the structure (sugar). The number of “saccharides in a given structure determines which class/category it falls under (see chart below). Glucose is transported around the body via the circulatory system (heart, veins, arteries, capillaries) and uptaken by specific tissues and organs like skeletal muscle and the liver. Once this uptake occurs 1 of 2 situations happen, the glucose gets stored in the tissue/organ OR the glucose get utilized to produce energy for necessary cellular functions. Our digestive system is basically a currency converter which takes carbohydrate and converts it to a currency that our body accepts (glucose).
The Importance of fibre:
Fibre can be broken down into various subcategories including: Dietary and Functional, Soluble and Insoluble. Within the first group the former is a non-digestible carbohydrates naturally found intact in plants while the latter is isolated carbohydrates which have been either extracted or manufactured for human consumption. Within the second group -Soluble and Insoluble- the categories are based on the fibres ability to dissolve is water (H2O). Pectin, gums, mucilages are examples of soluble fibres while cellulose, hemicellulose, lignin are non-soluble examples. Fibre has several vital functions including:
- Alters small intestine transit time
- Increases bile acid excretion
- Lowers cholesterolemia
- Attenuates the glycemic response to food
- Forms substances that delays release of stomach contents
It is also worth noting the interaction between fibre and the bacteria in our colon. Soluble fibre can be fermented by our bacteria to obtain energy or produce compounds that promote their growth. One compound that is particularly important is the production of short-chain fatty acids which can be used by the human body for various health mechanisms.
- Provide energy for colonic cells
- Inhibit hepatic cholesterol synthesis
- Enhance colonic blood flow
- Enhance immune function
- Prevent the growth of potentially harmful cells