Using the Glycemic Index to Manage Blood Glucose in Gestational Diabetes
While it is easy to limit foods high in added sugars, it can seem more difficult to know which complex carbohydrates – often referred to as starchy carbohydrates – to include within the diet when you have a diagnosis of gestational diabetes.
This group of foods includes bread, pasta, potatoes, breakfast cereals, couscous, rice and other grains. One of these foods should always be present at a meal, as they provide a source of energy through the provision of glucose. This means that they raise the level of glucose in the blood, which is no bad thing, as the aim of good glycemic control is to maintain blood sugars as constant as possible, though care still needs to be taken as to how much carbohydrate is included in a serving. It is also essential to be aware that some complex carbs can result in a blood sugar spike in a similar way as to when you eat sweet foods. So which are the best starchy carbohydrates to include at mealtimes to keep your blood glucose stable?
The Glycemic Index
At one time women with diabetes during pregnancy were advised to simply eat those carbohydrates which are high in fiber to aid their blood sugar control. However, it is now appreciated that, for instance, wholemeal and white bread raiseblood sugar levels very similarly and instead you are better choosing multigrain bread. While a high fiber carbohydrate is still a better choice in view of its nutrient content – beyond fiber they tend to be higher in various B vitamins and minerals vital during pregnancy – it does not guarantee they are better for controlling diabetes. This is because although the fiber content of a food can slow down how quickly it is broken down into sugars, this is just one of the factors that influence the rise in blood glucose. Additionally, it is soluble fiber found in the likes of fruit, vegetables and pulses which enables this rather than the insoluble fiber found in cereal products. How quickly a food raises glucose in the blood is termed its glycemic index, with those with a low glycemic index increasing it more slowly and being more favorable in diabetes.
Making low GI choices
Unfortunately there is not necessarily a rule you can follow as to which carbs are classified as low glycemic index and the easiest way to be sure is to refer to one of the official tables that list foods according to this value. However, here we provide an overview of which complex carbohydrates to choose in terms of their GI:
· Bread – multigrain, rye, soya and linseed, and sourdough
· Breakfast cereals – porridge, unsweetened muesli, All-bran and Special K
· Grains – long grain, brown or Basmati rice, pearl barley, bulgur wheat and quinoa
· Potatoes – new potatoes or sweet potato
· All pasta and noodles
· Crackers – oatmeal based or Ryvita
Bear in mind that cooking and processing foods can alter their glycemic index, so pasta cooked al dente has a lower score than that cooked till it is soft, and an intact potato is a better option than one that has been mashed. As very rarely do you eat a food in isolation, the other foods that you include at a meal can alter the GI favorably, as any food that contains protein or fat helps to slow down the digestion and release of sugars from carbohydrates. This means that even if you choose a higher glycemic index carb such as a baked potato, serve it with cottage cheese or tuna and it will have less impact on your blood sugars.
It is also helpful to know that all pulses (peas, beans and lentils), vegetables and fruit with the exception of a few such as ripe bananas, juice and dried fruit, milk and yogurts also have a low GI. As a general rule, the riper a fruit, the higher its glycemic index is because more of the starch has been converted to sugar.
Besides helping to achieve better glycemic control, choosing lower GI foods can also help to reduce cravings for sugary foods, which some women can find to be a problem during pregnancy. While this is in part due to changes in hormone levels, fluctuations in blood sugars can also be a contributing factor; keeping levels of glucose in the blood stable through choosing slow release carbs can prevent hunger.
Women who have decided to give up cigarettes prior to conception can find cravings especially problematic, as replacing cigarettes with snack foods is often used as a way to distract from the urge to smoke. However, it is in both the woman’s interest and that of her unborn baby to remain free from tobacco, as smoking during pregnancy is known to increase the risk of gestational diabetes along with all the other detrimental affects it can have. There is also recent evidence to suggest that smoking while pregnant also makes obesity and diabetes more likely in their children when they are older. Finding healthy snack options such as chopped fruit, vegetable sticks with a low fat dip, a couple of crackers with cottage cheese or a pot of low fat unsweetened yogurt, can help on both counts.