Excerpts from Medical News Today written by Christian Nordqvist
Carbohydrates are called carbohydrates because the carbon, oxygen and hydrogen they contain are generally in proportion to form water with the general formula Cn (H2O)n. Carbohydrate is a major food source and a key form of energy for most organisms. When combined together to form polymers, carbohydrates can function as long term food storage molecules, as protective membranes for organisms and cells, and as the main structural support for plants and constituents of many cells and their contents.
Saccharides, or carbohydrates, are sugars or starches.
This is the smallest possible sugar unit. Examples include glucose, galactose or fructose. When we talk about blood sugar we are referring to glucose in the blood; glucose is a major source of energy for a cell. In human nutrition, galactose can be found most readily in milk and dairy products, while fructose is found mostly in vegetables and fruit.
This is when two monosaccharide molecules are bonded together. Disaccharides are polysaccharides – “poly…” specifies any number higher than one, while “di…” specifies exactly two. Examples of disaccharides include lactose, maltose, and sucrose. If you bond one glucose molecule with a fructose molecule you get a sucrose molecule.
Sucrose is found in table sugar, and is often formed as a result of photosynthesis (sunlight absorbed by chlorophyll reacting with other compounds in plants). If you bond one glucose molecule with a galactose molecule you get lactose, which is commonly found in milk.
Polysaccharide is a chain of two or more monosaccharides. The chain may be branched (molecule is like a tree with branches and twigs) or unbranched (molecule is a straight line with no twigs). Polysaccharide molecule chains may be made up of hundreds or thousands of monosaccharides.
Polysaccharides are polymers. A simple compound is a monomer, while a complex compound is a polymer which is made of two or more monomers. In biology, when we talk about building blocks, we are usually talking about monomers.
THE GLYCEMIC INDEX
Carbohydrates enter the bloodstream as glucose at different rates – high glycemic index (GI) carbohydrates enter the bloodstream as glucose rapidly, while low GI carbohydrates enter slowly because they take longer to digest and break down. A meal with lower GI carbohydrates will raise your blood glucose levels more slowly, and over a longer period – this is better for long-term health and body weight control. People who are relatively physically inactive (sedentary), and don’t sleep at least 7 hours every night are especially vulnerable to the long-term detrimental effects of regular consumption of high GI carbohydrates.
Low GI carbohydrates have the following benefits:
- You are less likely to put on weight;
- You are more likely to lose weight if you are overweight
- You will have better diabetes control
- Your blood cholesterol levels will most likely remain healthy
- Your risk of heart disease is lower
- It will take longer for you to become hungry after a meal
- Your physical endurance will improve
How can I switch to a low GI lifestyle?
- If you eat cereals for breakfast, switch to oats, barley or bran. Make sure the oats are as natural as possible; milling or grinding can ramp up their GI dramatically.
- If you eat bread, only consume wholegrain bread.
- Eat plenty of fresh fruit and vegetables.
- If you have a fruit juice make sure you eat all of the pulp (the meat of the fruit).
- Eat rice with the husk still there (wild rice).
- If you eat pasta go for whole grain ones.
- Eat plenty of salads.
- Cut out all junk foods, processed foods, foods with too many additives (flavorings, emulsifiers, etc).
- Slow carbs matter much more than low carbs. A well balanced diet consisting of good quality foods is as important as physical activity and good sleep.
- Physical activity is a key factor in weight control and good long-term health. It is as important as a good diet and good sleep.
- Sleeping at least 7 hours each night is as important as a well balanced diet and physical activity.
If you are overweight and you want to lose weight, focusing on slow carbs is useful. A well balanced and nutritional diet, such as the Mediterranean diet, plus good sleep and plenty of physical activity, is much more likely to lead to long-term success and good physical and mental health.