How Does Food Affect Your Blood Sugar?

Test your diabetes smarts.

Medically Reviewed by Michael W. Smith, MD on September 15, 2015
From the WebMD Archives

When you have diabetes, your blood sugar level reflects the foods you choose.

"For over a year, my sugar ran from 250 to 350 every day," writes WebMD Diabetes community member chui55. After switching from chips and sweets to fruits, vegetables, and lean meats, "my sugar is ranging between 110 and 185... I am so glad I have turned a major corner now and [am] on my way to a healthier me."

Do you know which foods can help you control blood sugar? Take this quiz to find out.


1. The glycemic index ranks foods based on:

a. The amount of sugar they contain

b. How much weight gain they cause

c. How much they raise blood sugar

d. Their calorie count


2. Which of these breads is lowest on the glycemic index?

a. White

b. Pumpernickel

c. Whole wheat

d. 100% whole grain


3. Which of these vegetables is your best choice if you have diabetes?

a. Baked potato

b. Carrots

c. Corn on the cob

d. Sweet potato


4. Which of these nuts might help control your blood sugar?

a. Cashews

b. Hazelnuts

c. Pecans

d. All of the above


1. c. The glycemic index ranks carbohydrate-based foods based on how much they raise blood sugar levels. Foods that are high on this index can cause blood sugar to spike, making diabetes harder to control.

2. d. Breads that are 100% whole grain are made with the entire grain -- unlike refined grains, which are processed to remove some of the nutrient-dense layers. Whole-grain foods are high in nutrition and are slow-burning, so they help keep your blood sugar steady.

3. b. Though carrots can be sweet, they’re lower on the glycemic index than the other vegetables on this list. Green, leafy vegetables are an even better addition to your plate. Ideally buy vegetables fresh, or look for frozen or canned options with no added sauces or salt.

4. d. A review of 12 studies showed all kinds of tree nuts -- from Brazil nuts to walnuts -- improved A1c and fasting blood sugar levels. Peanuts weren’t included in the research -- they’re legumes, not nuts. Add tree nuts to your daily diet, but don’t go overboard because they are high in fat and calories. People in the studies ate about 2 ounces of nuts a day (that’s about 40 almonds or 14 walnuts).

Ask Your Doctor

Which foods can help stabilize my blood sugar?

What size portions should I eat?

Can I snack between meals? What are the best snacks?

What should I do if my blood sugar stays high?

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Show Sources


Allen, RW. Annals of Family Medicine, September-October 2013.

American Diabetes Association.

American Heart Association.

Harvard Medical School.

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