One important characteristic that differentiates a healthy from an unhealthy carbohydrate-rich food, is the glycemic index of that food.
How the glycemic index works
The glycemic index is a measure of the speed at which glucose enters the bloodstream after eating it. Sodas and candy, for example, are high in simple sugars like sucrose and glucose. After eating these, the body is able to quickly digest and absorb the glucose in these foods, leading to a spike in blood sugar levels. The body responds by releasing large amounts of insulin, the hormone responsible for lowering blood sugar levels. Because the vigorous insulin response to the spike in blood glucose is reactive, the response results in a period of time when blood sugar levels may actually fall into the lower range of normal.1 This dip in blood sugar leads to the sensation of hunger and explains why we can feel hungry soon after eating a snack that’s high in simple sugars. Some scientific studies show that high levels of glucose and insulin in the blood may be associated with higher rates of cholesterol synthesis in the body.
Which foods are best for stabilizing blood sugar and insulin levels?
In general, meals and snacks that contain fiber, protein, and/or healthy fats are far better choices for stabilizing blood sugar and insulin levels. Also, they can help to delay the return of hunger. Brown rice and whole-wheat bread, for example, each have a lower glycemic index than white rice and white bread. Sensible, low-glycemic snacks, like a slice of low fat cheese with a whole-grain cracker, an avocado and tomato sandwich on whole-grain bread, or a handful of raw, unsalted almonds will stabilize blood sugar levels much more effectively than snacks like potato chips and sweetened drinks. Because of the associated fiber, whole fruits are sensible treats with a lower glycemic index than candy bars or processed, sugary desserts.
By Maya Adam, MD, Adapted from Food, Love, Family, A Practical Guide to Child Nutrition
1. Ludwig DS. "The Glycemic Index: Physiological Mechanisms Relating to Obesity, Diabetes, and Cardiovascular Disease." JAMA: The Journal of the American Medical Association. 2002;287(18):2414–2423.