What are carbohydrates? A simple question but it never fails to amaze me how many people sit before me in my practice and do not know the answer to this question. I don’t think that this is the fault of the individual, but of health care professionals, for automatically presuming that everyone understands what ‘carbs’ are all about and how they affect diabetes. To have an understanding of carbohydrates is integral to managing diabetes and diet well.
All carbohydrate foods are digested in the body to produce glucose. The amount of carbohydrate that you eat and the type of carbohydrate that it is determines how your blood sugar levels rise after meals. Eating too much carbohydrates &/or eating simple carbohydrates that have a high glycaemic index can cause blood sugar levels to rise to quickly and too high after a meal. Usually it takes the body one and a half to two hours to digest and release sugar into the blood stream when you have eaten carbohydrates and this is why we often ask people with diabetes to take their blood sugars two hours after a meal otherwise known as ‘post prandial’ blood sugars. This is to determine whether the types of foods are affecting your blood sugar levels, is your medication working or if you are on insulin.
Carbohydrates are very important to the body, as they are the bodys main source of fuel. Eating regular meals throughout the day, with carbohydrates spread evenly across these meals, will maintain your energy levels without allowing your blood sugar levels to rise sharply. Carbohydrates are vital, for everybody, including people who have diabetes. But how you source your carbohydrates is what makes all the difference to your blood sugar levels when you have diabetes.
Carbohydrates or ‘starches’ as they are also known as, are derived from plants e.g: grain, vegetables and fruit. They are broken down at different speeds in [pull_quote align=”left”]Carbohydrates are vital, for everybody, including people who have diabetes[/pull_quote]the body and this is very important to be aware of when you have diabetes, as the rate at which carbohydrates are metabolised by the body can have a direct impact on blood sugar levels. Carbohydrates are usually split into two distinct groups, simple and complex carbohydrates. Simple carbohydrates are fast acting, readily absorbed such as cakes, sweets, biscuits, white bread and sugary drinks. Complex carbohydrates are more slow acting, taking time to digest and absorb, such as brown breads, whole wheat rice and pasta, therefore making them an ideal carbs for people with diabetes. The glycaemic index or GI is the best way for explaining how carbohydrates affect blood sugar levels. For further information on GI, I recommend people with both Type 1 & Type 2 diabetes to use the Rick Gallop GI diet, which is widely available in bookshops across Ireland or to go to http://www.gidiet.com/. People with diabetes are advised to stay away from high GI foods.
Some of the dietary sources of carbohydrates are as follows:
- Glucose: commercially prepared from starch & is found in some fruits
- Fructose: found in honey and some fruits, known as ‘fruit sugar’
- Sucrose: obtained from sugar beet & sugar cane and is commonly known as ‘table sugar’
- Lactose: Found in milk
- Maltose: usually used in the manufacture of beer
- Starch: Grains, unripe fruits, vegetables
Sugars that are derived from dietary carbohydrates are utilised in three ways: They are metabolised to produce energy, they are converted to glycogen and stored in the liver & muscles for when they are needed and finally, converted to fat when there is an excess of glycogen in the muscles and liver, which is stored in the adipose tissues.
The body maintains sugar levels in the blood at all times between 3.5 – 10m/mmol/l, but in people who have diabetes, they cannot metabolise carbohydrate correctly and glucose rises above this level.
The American Diabetes Association recommends that the RDA (recommended daily allowance) for carbohydrates is 130grams, as this is the amount of carbohydrate that is utilised by the brain daily. The standard recommendation for carbohydrate is 45-65% of total calories. This means if 1800 calories are eaten each day, the recommended amount of carbohydrate is 202-292 grams based on 45-65% calories from carbohydrate. According to the American Diabetes Association, diabetics should limit the amount of carbohydrates consumed to 45 to 60 grams at one meal in order to avoid dangerous spikes in blood sugar levels.
An example of simple/complex carbohydrate choices are as follows:
[one_half]Best Choices[/one_half] [one_half_last]Worst Choices[/one_half_last]
[one_half]Whole grain flour[/one_half] [one_half_last]White flour[/one_half_last]
[one_half]Porridge, Bran[/one_half] [one_half_last]Breakfast cereals[/one_half_last]
[one_half]Wholegrain Bread[/one_half] [one_half_last]White Bread, cakes, biscuits[/one_half_last]
[one_half]Fresh/Frozen vegetables[/one_half] [one_half_last]Canned vegetables[/one_half_last]
[one_half]Frozen fruit or canned in fruit juice[/one_half] [one_half_last]Canned fruit in syrup[/one_half_last]