Good Versus Bad Carbohydrates: Know the Difference
The Details on Complex Carbohydrates
Complex carbohydrates are considered "good" because of the longer series of sugars that they are made of, which the body takes longer to break down. That means you will get lower amounts of sugars released at a more consistent rate — instead of peaks and valleys — to keep you going throughout the day.
Foods with complex carbohydrates also typically have more vitamins, fiber, and minerals than foods containing more simple carbohydrates.
Nutrient-dense complex carbs that are part of a healthy, balanced diet include:
• Leafy greens – spinach, romaine lettuce, arugula, kale, butter lettuce
• Cruciferous vegetables – cabbage, broccoli, brussels sprouts, cauliflower
• Legumes, such as black beans, chickpeas, lentils, and others
The Glycemic Load Factor
Describing carbs as either simple or complex is one way to classify them, but nutritionists and dietitians now use another concept to guide people in making decisions about the carbs they choose to eat. The glycemic index (GI) of a food basically tells you how quickly and how high your blood sugar will rise after eating the carbohydrate contained in that food, as compared with eating pure sugar. Foods with a high GI are easily digested and cause a quick rise in blood sugar. Foods with a lower GI get digested more slowly.
Knowing the GI for a specific food can help you understand how the carbs in that food will affect your blood sugar, but it’s important to point out that it doesn’t necessarily make a food unhealthy or healthy. Fruits like watermelon and cantaloupe both have a high GI even though both are healthy foods. You can look up a food's GI using the online international GI database.
To take this approach one step further, you want to look at the glycemic load of a food. The glycemic load factors into account both glycemic index and how much carbohydrate is in the food. To determine glycemic load, you multiply a food's glycemic index number by the amount of carbohydrate the food contains per serving and divide by 100.
A low GL is 10 or less; medium is 11 to 19; and 20 or greater is considered high. For example, a plain bagel has a GI of 72 and GL of 25, while whole-wheat bread has a GI of 69 and GL of 9. GL can also be used to compare the effect of carbohydrates on blood sugar in entire meals or snacks, whereas the GI for a food is only indicative of one food at a time.
Even if a food contains carbs that have a high glycemic index number, if the amount of carbohydrate is low then it won’t have as much of an impact. A good example is watermelon, which has a GI of 80 but a GL of only 5. It tastes sweet, but it’s mostly water.
The bottom line: Carbs are not bad for you. Carbohydrates — both simple and complex ones — are part of a healthy diet. Just be sensible about the carbs you choose. Skip low-nutrient desserts, consider the levels of sugar and fiber, and focus on healthy vegetables, legumes and low glycemic fruits to get the energy your body needs every day.