Fitness Mantra : A Health and Fitness Blog

Glycemic Index: Some Foods Raise Your Blood Glucose Faster Than Others

07

April

(Part 2 of the Glycemia series: Glycemia | Glycemic Index | Glycemic Load)

When we last left Maria Sharapova in part one, Glycemia, of this three part series, she was sitting in her chair sulking over a dubious line call and chomping on a banana. The question uppermost in our minds - why a banana? Wouldn’t an apple or some other fruit do? And why not some of those so-called energy drinks?

To answer these questions, let’s quickly recap what we discussed in the first post:

Glucose (sugar) is the primary source of energy for the cells in our body
Glycemia is the concentration of glucose in the bloodstream
A fixed range of glycemia (typically 70-100 mg/dl) is required for the body to function normally
The hormone insulin acts as a regulator to enforce this range and does so by carrying off additional blood-glucose to the cells that need it for energy
In case there’s even more glucose than is currently required for the cells, the excess gets stored as fat

It is the 4th point above that is of concern to us now. While the ultimate digestive process in the intestines also causes glucose to enter the bloodstream, certain food sugars enter the blood stream directly from the stomach by a process called absorption. So if we are ever in need of a quick burst of energy, guess what kind of foods we should choose? That’s right - we should look for foods that give us that much-needed glucose ASAP! And how do we find such foods? Why, of course by looking up the …

Glycemic Index: Glycemic Index (GI) is a method that ranks foods based on how fast they raise glycemia.

Wikipedia explains …

Carbohydrates that break down rapidly during digestion have the highest glycemic indexes. Carbohydrates that break down slowly, releasing glucose gradually into the blood stream, have a low glycemic index.

Technically, the glycemic index of a food is defined by the area under the 2 hour blood glucose response curve following the ingestion of a fixed portion of carbohydrate (usually 50 g).

Generally, glucose is given the Glycemic Index value of 100 and all other foods are given numbers based on their effect on glycemia compared with glucose. I say “generally” because some scales use white-bread as a base reference (giving it 100) - in which case glucose becomes 140. This type of scale is useful for those who like to keep a food they see and eat everyday as a ready reference rather than pure glucose which we almost never get a chance to see in our daily lives. For the purposes of our discussion, we shall use glucose as the base (GI=100) - so no food shall have a GI greater than 100.

bananas raisins rice bowl potatoes

Here are the Glycemic Index values for some common foods (glucose=100):

Peanuts 14
Pizza 30
Lowfat yogurt 33
Apples 38
Carrots 47
Oranges 48
Bananas 52
Potato chips 54
Snickers Bar 55
Brown rice 55
Honey 55
Oatmeal 58
Ice cream 61
Raisins 64
White rice 64
Sugar (sucrose) 68
White bread 70
Popcorn 72
Baked potato 85
Glucose 100

For more information about GI, you can also visit GlycemicIndex.com, the “home of Glycemic Index and the GI database”. The site includes numerous resources such as a detailed description of how GI is measured, a monthly newsletter containing information about the latest developments in the world of GI and, most useful of all, a GI database with the current GI values of almost any food you could think of searching for.

All these features are available as links on the home page of GlycemicIndex.

Some reasons to eat low-GI foods:

Low GI diets help people lose and control weight
Low GI diets increase the body’s sensitivity to insulin and improve diabetes control
Low GI carbs reduce the risk of heart disease and blood cholesterol level

Essentially, since low-GI foods release their energy slowly to the body, they provide the body with a more uniform and continuous supply of energy preventing drastic fluctuations in blood-glucose levels (which in turn would wreak havoc on insulin production and utilization)

So when are the best times to eat high-GI foods? Pretty much right after exercise or strenuous activity. The high-GI carbs help re-fuel carbohydrate stores in our bodies.

Now that you are familiar with the term Glycemic Index and know the effect of high and low GI foods on our bodies it is becoming clearer why our tennis ace prefers bananas on the court as a mid-game snack. With a GI of about 52, it’s an ideal energy-booster. Also from the table listed above it is probably the most convenient to stash in a gym bag (try carrying a bowl of raw cooked rice!) and compared to a Snickers bar it is lower in fat and more healthful because it also contains vitamins and fiber with very little fat.

But wait, you say? You are not completely convinced with this explanation because you have been studying the table carefully and are starting to notice some strange things: apples have a GI of 38 (not too bad in comparison) and the good old carrot, a vegetable, has a GI of 47?

To get a quick energy-boost, wouldn’t Maria be way better off with an apple or carrots since these have similar GI profiles (and carrots actually have much less sugar and tons of vitamins to boot)? Actually she wouldn’t; but if you are having these doubts, then you are on the right track.

Stay tuned folks: this series wraps up with answers to this final conundrum in the last part of this series: Glycemic Load.

(Part 2 of the Glycemia series: Glycemia | Glycemic Index | Glycemic Load)

Technorati Tags: health, fitness, nutrition, glycemia, glycemic index, glycemic load

FitnessMantra Weekend: Children Are Targeted With Ads For Unhealty Products

01

April

Fitness Mantra del.icio.us page Welcome to “FitnessMantra Weekend”, your once-a-week health news update. As always you can also stay updated with the latest in fitness news by subscribing separately to the Fitness Mantra del.icio.us feed.

An acute problem these days is the number of commercials shown during children’s shows that feature sugar and fat-loaded products (usually promoted by some of the characters from the very show the kids were watching thus blurring the lines between the show and the commercial.

Children’s TV ads loaded with junk food proclaims the MSNBC news article about this topic:

“The vast majority of the foods that kids see advertised on television today are for products that nutritionists would tell us they need to be eating less of, not more of, if we’re going to get a handle on childhood obesity,” said Vicki Rideout of the Kaiser Family Foundation, which conducts health research.

The researchers monitored 13 television networks and found that children between teh ages of 8 and 12 saw almost 21 food-related commercials a day. And just what kinds of foods were these?

Of food ads that targeted children, 34 percent were for candy and snacks, 29 percent for cereal, 10 percent for beverages, 10 percent for fast food, 4 percent for dairy products, 4 percent for prepared food and the rest for breads and pastries and dine-in restaurants.

Yes you read that right: number of messages about fresh fruits and vegetables: zero. Read the full article to learn a few more shocking statistics. How do you solve this problem in your home? How do you respond when kids come up to you asking for a particular cereal or candy believing that the food has to be good because their favorite cartoon character is endorsing it? Do share your thoughts in the comments area.

The week’s top health and fitness stories follow:

Beyond Snack Packs: 22 Healthy Munchies: How Healthy Are 100-Calorie Snack Packs? And what alternatives could one turn to?
Diabetes Linked to Parkinson’s Disease: Having diabetes may increase the risk of developing Parkinsonâ€™s disease.
Exercise prevents repetitive strain injury: An active lifestyle outside of work may help protect against work-related repetitive strain injury, a Canadian study found.
Got a Fat Tooth?: Make way, sweet tooth; scientists believe we reach for the greasy french fries, creamy premium ice creams, butter, and other fatty foods because of a different culprit — the “fat tooth.”
High BMI has pros, cons in prostate cancer: A high body mass index (BMI) does not increase the risk of developing prostate cancer, but once the disease occurs, a high BMI is associated with a greater risk of dying from the cancer, researchers report.
Sedentary behavior linked to high blood sugar: People who tend to be sedentary — as indicated by the amount of time they spend watching television — are likely to have high levels of glucose in their blood, even though they may not be diabetic.
Children’s TV ads loaded with junk food: In a child’s buffet of food commercials, more than 40 percent of the dishes are candy, snacks and fast food. Nowhere to be found: fresh fruit, vegetables, poultry or seafood.
Portion control ‘the way to healthier eating’: SMALLER size packs of chocolate, crisps and other foods should be encouraged to help people eat more healthily, the official food watchdog said yesterday.
Dodge Type 2 Diabetes With Extra Dairy and Activity!: Key lifestyle components to reduce the risk of diabetes include a moderate-calorie, lower-fat diet that supports weight loss coupled with increased physical activity. Beyond that, recent research indicates that dairy products may offer additional diabetes
Obesity shortens kids’ life spans: The childhood obesity “epidemic” is so disturbing that today’s children will become the first generation in some time to have a shorter life expectancy than their parents, a new report says.
High Trans Fat Intake Triples Heart Disease Risk: Women who eat diets rich in unhealthy trans fats have three times the risk of heart disease as those with the lowest intake, a new study finds.
Healthy pizza not a half-baked idea: It’s the junk food junkie’s wildest dream come true - pizza as health food.
Sally Squires - Can a Healthy Snack Be Tasty?: Question is: How do the fairly-good-for-you [snack] items taste?
Longer journeys to school drive obesity: According to the research from Loughborough’s School of Sport and Exercise Science - which didn’t look at diet - one of the biggest causes of young people’s sedentary lifestyles was the growth in the amount of time they spent in the car.
‘Good fat’ diet OK for heart attack: A Mediterranean-style diet high in olive oil and other healthy fats is just as good as the classic American Heart Association low-fat diet for the 8 million Americans who have suffered a heart attack and want to prevent a repeat, new research sugges
Blueberries tackle bowel cancer: A compound in blueberries may be good for preventing bowel cancer, US scientists believe.