All Carbs Are Not Created Equal

M. Kathleen Figaro, MD, MS, FACE

If you have type 2 diabetes, which occurs when your insulin does not work as well as it should to help cells take in glucose for energy, accompanied by a decrease in production of insulin by your pancreas, you might have been advised that weight loss is an important part of managing the condition. Losing weight means you need to increase your physical activity while also decreasing your calorie intake. This is when the dreaded “diet” enters the picture.

There’s certainly a huge variety of diets, ranging from low-fat to very-low-carbohydrate regimen. So, why don’t all (or some) diets result in weight loss and weight-loss maintenance?

One explanation for the difficulty of keeping weight off may be the challenge of sticking with a diet plan. Telling yourself to eat less and making informed choices with every morsel you choose to eat (or not) is challenging — especially in country with readily available, highly caloric foods. And when one is bombarded by ads everywhere that make foods look delicious and imply that you can eat and not have to account for calories, that makes dieting even more difficult.

When you’re not able to lose weight, or keep it off if you do lose weight, a crucial factor to consider is the actual makeup of your meal choices, not just total calorie count alone. This is where the concept of the glycemic index of food comes into play.

Just what is the glycemic index and how does it impact you as a patient with diabetes?

The glycemic index (GI) is a relative ranking of carbohydrates in foods according to how they affect blood glucose (sugar) levels. Foods that are low on the glycemic index scale tend to release glucose slowly and steadily, while foods high on the index release glucose more rapidly. This is important to know because if you’re getting too much glucose, it leads to high blood sugar that your body can’t break down quickly enough, which it subsequently stores as fat.

People with type 1 diabetes (the diabetes that results from loss of the ability of the pancreas to produce insulin), as well as some with type 2 diabetes, cannot produce enough insulin or produce and release it fast enough, so they are likely to have high blood glucose after a meal. Although short-acting insulins are relatively fast-acting after injection, they are not as fast as your own body’s ability to produce and get insulin into the body. Thus, you can help better control your blood glucose levels through the slow and steady release of glucose found with low-glycemic-index foods.

Diets with a lower glycemic index and higher protein content tend to improve diet success and weight-loss maintenance compared to those diets with a higher glycemic index. An important note: foods that are close to how they're found in nature tend to have a lower glycemic index than refined and processed foods.

But the glycemic index is only one part of the equation. To understand a food’s complete effect on blood sugar, you need to know not only how quickly the food you’re eating causes glucose to enter the bloodstream, but also how much glucose it will deliver. This is a separate value called glycemic load.

The glycemic load (GL) gives a more accurate picture of a food’s impact on blood sugar and is determined by multiplying the grams of carbohydrates in a serving of food by the food’s glycemic index, then dividing that number by 100. A glycemic load of 10 or below is considered low, while 20 or above is considered high.

Confused? Let’s look at some examples. You can find the grams of carbohydrate of many foods on the product label, or use many good apps on your phone, tablet or computer to help with this exercise (one good source is Melon, for example, has a glycemic index of 70, but a small, cup-size serving has so few carbohydrates in it that its glycemic load is actually low. On the other hand, orange juice has a glycemic index of 50, but a serving size has more calories and carbohydrates, so it has a slightly high glycemic load of 12. Portion sizes matter too, when you try to decide how a food will affect your blood glucose. Please check out the next page for other examples.

As mentioned earlier, the addition of protein or substitution of carbohydrate with protein could help you feel fuller and give a better sense of satiety. Some now even recommend a small amount of fat to a diet — but be cautious, as one gram of protein and one gram of carbohydrate each contain only 4 calories, while a gram of fat contains 9 calories. Make your choices wisely. And remember, the fat should be a good fat, not saturated fat.

So, if you want to lower your weight as well as achieve better control of your diabetes, in addition to lowering your total daily calories, try:

  • More whole grains, nuts, legumes, vegetables without starch, limit ripe fruits
  • Fewer foods with a high glycemic index, like potatoes, white rice, and white bread
  • Less sugary foods, including candy, cookies, cakes, and sweet drinks
  • More foods with slow release of sugars and starches like old-fashioned oats and tart berries

Eat in moderation and be choosy about what you choose to eat.

Food Glycemic Index Serving Size Glycemic Load Per Serving
Apple (with skin) 39 138 grams (medium) 6.2
Apricots (canned) 64 1 cup 24.3
Banana 51 118 grams (medium) 12.2
Cantaloupe 65 1 cup 7.8
Fruit Cocktail 65 214 grams (1 cup) 19.8
Grapes 43 1 cup 6.5
Grapefruit 25 123 grams (1/2 fruit) 2.8
Mango 51 165 grams (1 cup) 12.8
Orange 48 140 grams (1 fruit) 7.2
Peach 28 98 grams (medium) 2.2
Peaches (canned) 52 1 cup 17.7
Pear 33 166 grams (medium) 6.9
Pears (canned) 44 1 cup 12.3
Pineapple 66 1 cup 11.9
Raisins 64 43 grams (small box) 20.5
Strawberries 40 1 cup 3.6
Watermelon 72 1 cup 7.2
Beets (canned) 64 ½ cup 9.6
Broccoli 0 ½ cup 0.0
Cabbage (cooked) 0 ½ cup 0.0
Cauliflower 0 1 cup 0.0
Celery (raw) 0 1 stalk 0.0
Corn (yellow) 55 1 cup 61.5
Green beans 0 1 cup 0.0
Mushrooms 0 1 cup 0.0
Peas (frozen) 48 ½ cup 3.4
Potato (baked) 111 150 grams 33.0
Potato (boiled) 82 150 grams 21.0
Spinach 0 1 cup 0.0
Sweet Potatoes 54 1 cup 12.4
Tomato 38 123 grams (medium) 1.5
Baked Beans 48 1 cup 18.2
Chickpeas (boiled) 31 1 cup 11.3
Kidney Beans 27 1 cup 7.0
Lentils 29 1 cup 7.0
Lima Beans 31 1 cup 7.4
Peanuts 13 1 cup 1.6
Pinto Beans 39 1 cup 11.7
Soy Beans 20 1 cup 1.4
Ice Cream 38 ½ cup 6.0
Low-Fat Ice Cream 47 ½ cup 9.4
Whole Milk 40 1 cup 4.4
Plain Yogurt 36 1 cup 6.1
Bagel 72 89 grams (1/4 inch) 33.0
White Bread 70 1 slice 8.4
Wheat Bread 70 1 slice 7.7
Pita Bread 68 30 grams 10.0
Hamburger Bun 61 30 grams 9.0
Brown Rice 50 1 cup 16.0
White Rice 89 1 cup 43.0
Quinoa 53 1 cup 13.0
Hummus 6 30 grams 0.0
Cheese Pizza 80 100 grams 22.0
Popcorn 55 1 cup 2.8