Diabetes Forecast

What Affects My Blood Glucose?

I have type 2 diabetes, and my A1C is about 6 percent. I really don't understand how caloric intake affects my blood glucose. Suppose that I ate a meal of meat, potato, vegetable, apple pie, and milk, in quantities that I got 100 calories from each. Would each contribute an equal amount to my blood glucose? Barney Considine, Missoula, Montana

Madelyn L. Wheeler, MS, RD, CDE, FADA, CD, responds:

Blood glucose comes mainly from the carbohydrates in food you eat (it's also affected by how physically active you are). Your body breaks the carbs down into glucose, which supplies you with energy or is stored as fat. The hormone insulin helps usher glucose into the cells. Having type 2 diabetes usually means that your body doesn't respond properly to insulin, produce enough insulin, or both.

In the meal you describe, 100 calories from each of the five foods would not affect your blood glucose equally because their carb content differs. Plain meat, fish, poultry, and fats such as margarine or butter do not contain carbohydrates. The other food groups (starches, nonstarchy and starchy vegetables, fruits, milk and other dairy products such as cheese, and other "combination" foods such as desserts) all contain carbs.

The table below shows the weight or volume and carb content for 100 calories of each of the five foods.

Food Weight/Volume Carbohydrate (grams) Calories
Meat (hamburger, 96% lean) 2 oz. 0 100
Potato (boiled plain) 2/3 cup 23 100
Nonstarchy Vegetable (green beans) 2 1/2 cups 23 100
Apple Pie 1 1/3 oz. 14 100
Milk (nonfat) 1 1/4 cups 15 100

As you can see, it takes 2 1/2 cups of a nonstarchy vegetable like green beans to total 100 calories, much more than a starchy potato, even though both have 23 grams of carbs. Green beans have a low calorie (energy) density. They contain a lot of water and so are very filling. Apple pie, which is packed with fat and sugars, has a high calorie density. Just a small amount produces many calories.

A healthy meal plan will include a variety of foods. If you are overweight, counting calories may help with shedding pounds. Losing weight can help your body use insulin more effectively and improve blood glucose control. That, in turn, helps you avoid diabetes complications. Your A1C is evidence of good control; congratulations for keeping it on target.



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