Fiber and the Glycemic Index

Fiber is an influential player in any diet, including a low-glycemic one for both weight loss and blood sugar control. The term fiber is used to describe complex carbohydrates that your body can’t break down. Because your body can’t break it down and absorb it, fiber has no calories.

Glycemic index: Soluble fiber, insoluble fiber

Following a low-glycemic diet is about managing your blood sugar so you avoid large insulin spikes throughout the day. Fiber is a natural part of this process. Along with its other weight-loss benefits, fiber helps control the rise of blood sugar in your body after a meal. This effect is found specifically in soluble fiber, which dissolves and becomes gummy. Soluble fiber is also great at reducing cholesterol levels. Insoluble fiber, which people often consider “roughage,” is also beneficial. It works as an appetite suppressant, slows the rate that blood accepts the blood glucose that’s formed from digested sugars and starches, prevents constipation, and decreases your risk for bowel diseases.

Specific foods high in both soluble and insoluble fiber include:

• Soluble-fiber foods: Beans, peas, oats, barley, flaxseeds, and many fruits and vegetables (such as apples, oranges, and carrots).

• Insoluble-fiber foods: Whole-wheat bread or pasta, corn bran, and many vegetables (such as green beans, cauliflower, and potatoes). The tough, chewy texture of these foods comes from the fiber itself.

The fiber content of vegetables and fruits varies considerably. For example, applesauce doesn’t give you as much fiber as an apple with the skin on. Similarly, a large bowl of salad using only Romaine lettuce has around 1 gram of fiber compared to almost 4 grams of fiber for 1 cup of boiled collard greens. This simple fact is why aiming for a variety of fruits, vegetables, beans, and grains is the way to go.

How to choose foods for a glycemic-index diet

Choosing foods that are low-glycemic and high in fiber is your secret weapon for weight loss. This power-duo combination adds up to

• Lower blood sugar and insulin spikes

• Controlled food cravings

• A longer-lasting “full” feeling

• Fewer calories and more volume consumed

So how to make sure you’re getting enough fiber out of the large variety of low-glycemic fruits, vegetables, beans, and whole grains you’re eating? Good news! You don’t need to mess with counting fiber grams. Instead, just aim for the following:

• Three or more servings of vegetables each day

• Two or more servings of fruits each day

• Three or more servings of whole grains each day (out of your total grain intake)

• One or more servings of legumes (beans, peas, and lentils) each day

Meeting your fiber quota while incorporating low-glycemic food choices into your weekly meal plans is easier than you may expect. Try the popular low-glycemic/high-fiber foods in this table: