Carbs: How to separate the good from the bad

  • By Elizabeth Smoots Herald Columnist
  • Monday, October 22, 2007 6:54pm
  • Life

Are carbohydrates good or bad?

Carbohydrates are not all the same. Different types have good or bad effects on your body that influence your health.

Scientists can determine these effects using two methods, called glycemic index and glycemic load, which look at the quality and quantity of carbohydrates in food.

Accurate measurements are available, and long have been used in Canada, Australia and Europe. But the concepts have not yet gained widespread acceptance in the U.S.

Time for a greater understanding of carbs in this country? I think knowledge of these measurements can help some people at risk for diabetes, obesity or heart disease as well as those interested in a healthy diet.

What is the glycemic index?

The glycemic index measures the ability of carbohydrates in foods to increase your blood sugar levels.

The speed at which a particular carbohydrate raises blood sugar relates to its chemical structure, the food’s surface area available for digestion and the presence of fiber or fat.

In the rating system, each food is compared with the effects of pure glucose (rated 100). Foods with a high glycemic index (more than 70) are digested quickly, providing you with fast burst of energy followed by an energy drop.

On the other hand, low-GI foods — those with a GI under 55 — release energy slowly over a longer period of time.

The rate of glucose absorption is the main determinant of how healthful or harmful a carbohydrate is for your body.

How is GI measured and used?

The GI score of common foods is analyzed in several laboratories around the world, including the Sydney University Glycemic Index Research Service in Australia. It’s based on the average blood-glucose response of 10 healthy volunteers over a period of two hours to a portion of food that contains 50 grams of digestible carbohydrate.

The GI score can be used to determine the carbohydrate quality of particular foods. Lower GI scores are usually associated with high-quality, wholesome foods such as vegetables, fruits, beans and whole grains.

Higher GI scores tend to go along with less-nutritious processed foods such as French fries, cakes, white bread or white rice.

You can use the GI scores to identify your best carbohydrate choices.

What are the health effects?

Recent Harvard research has linked an excess of high-GI foods with a greater risk for diabetes, obesity and heart disease.

In contrast, a diet that emphasizes low-GI foods is associated with less hunger and weight gain, more sustained energy and endurance, lower cholesterol levels and reduced risks for heart disease and diabetes.

How does glycemic load differ?

How high your blood glucose rises, and how long it remains high, depends on the quality and quantity of carbohydrates you ate at a meal.

The GI measures the quality. Glycemic load looks at both the quality and quantity to determine a food’s overall effect on your blood sugar level.

The formula for GL is (GI times the grams of carbs per serving) divided by 100.

It allows you to determine, for instance, that a small baked potato with a GL of 12 will have twice the metabolic effect on your blood sugar level as an apple with a GL of six.

Both measurements are useful. The GL helps you select portion sizes while GI helps you differentiate between good and bad carbohydrate choices. A healthy diet includes a variety of predominantly low-GI foods.

For more information: Glycemic Index Database, www.glycemicindex.com .

Contact Dr. Elizabeth Smoots, a board-certified family physician and fellow of the American Academy of Family Physicians, at doctor@practicalprevention.com. Her columns are not intended as a substitute for medical advice or treatment. Before adhering to any recommendations in this column consult your health care provider.

&Copy; 2007 Elizabeth S. Smoots

Talk to us

> Give us your news tips.

> Send us a letter to the editor.

> More Herald contact information.

More in Life

Everett P. Fog, 15, in front of an Everett mural along Colby Avenue on Wednesday, Jan. 22, 2025 in Everett, Washington. (Olivia Vanni / The Herald)
Hello, Everett! No escape when your name is same as the town

Everett P. Fog, 15, sees and hears his first name wherever he goes. His middle name is also epic.

Jared Meads takes a breath after dunking in an ice bath in his back yard while his son Fallen, 5, reads off the water temperature on Tuesday, Oct. 15, 2024 in Everett, Washington. (Olivia Vanni / The Herald)
Chill out: Dive into the cold plunge craze

Plungers say they get mental clarity and relief for ails in icy water in tubs, troughs and clubs.

Schack exhibit to highlight Camano Island watercolorists

“Four Decades of Friendship: John Ebner & John Ringen” will be on display Jan. 16 through Feb. 9.

XRT Trim Adds Rugged Features Designed For Light Off-Roading
Hyundai Introduces Smarter, More Capable Tucson Compact SUV For 2025

Innovative New Convenience And Safety Features Add Value

Sequoia photo provided by Toyota USA Newsroom
If Big Is Better, 2024 Toyota Sequoia Is Best

4WD Pro Hybrid With 3-Rows Elevates Full-Size

2025 Toyota Land Cruiser (Provided by Toyota).
2025 Toyota Land Cruiser revives its roots

After a 3-year hiatus, the go-anywhere SUV returns with a more adventurous vibe.

Enjoy the wilderness in the CX-50. Photo provided by Mazda USA Newsroom
2025 Mazda CX-50 Adds Hybrid Capability to Turbo Options

Line-Up Receives More Robust List Of Standard Equipment

Practical And Functional bZ4X basks in sunshine. Photo provided by Toyota Newsroom.
2024 bZ4X Puts Toyota Twist On All-Electric SUV’s

Modern Styling, Tech & All-Wheel Drive Highlight

Photo provided by Mazda USA Newsroom
2025 Mazda3 Turbo Premium Plus Hatch Delivers Value

Plus Functionality of AWD And G-Vectoring

2025 Mazda CX-90 Turbo SUV (Provided by Mazda)
2025 CX-90 Turbo models get Mazda’s most powerful engine

Mazda’s largest-ever SUV is equipped to handle the weight, with fuel efficiency kept in check.

Provided by Bridges Pets, Gifts, & Water Gardens.
Discover where to find the best pet supplies in town

Need the perfect store to spoil your furry friends? Herald readers have you covered.

VW Jetta SEL is a sedan that passes for a coupe. Photo provided by Volkswagen U.S. Media.
2025 VW Jetta Offers Greater Refinement, Technology And Value

A Perfect Choice For Small Families And Commuters

Support local journalism

If you value local news, make a gift now to support the trusted journalism you get in The Daily Herald. Donations processed in this system are not tax deductible.