Glycemic
Index, what is it?
Glycemic index (GI) is measurement of the rate at which
carbohydrates convert to glucose in the blood and cause blood
sugar to rise. A scale of 0-100 is used, with pure glucose being
100.
Glycemic Index is it important?
The body performs best when the blood sugar level is kept
relatively constant. If the blood sugar drops too low, you can
become lethargic and/or experience increased hunger. If it goes
too high, your brain signals your pancreas to secrete more
insulin which brings the blood sugar back down. Unfortunately
this process converts the excess sugar to stored body fat. The
greater the rate of increase in blood sugar, the greater the
chances that more chance that the body will release excess
amounts of insulin, which will drive your blood sugar down too
low. Consequently, eating foods that cause rapid/large glycemic
responses may give you an initial elevation in energy as your
blood sugar rises. However, this rise in blood sugar is usually
followed by a cycle of lethargy, more hunger and increased fat
storage.
Even though increased fat storage sounds bad enough, individuals
with diabetes mellitus, types 1 and 2 have an even greater
problem. Their bodies are unable to secrete or process insulin
which causes their blood sugar to rise too high, leading to a
host of additional other serious problems.
While many sugary, sweet tasting foods do have high GI numbers,
some starchy foods like potatoes and white bread score
even higher than honey or table sugar (sucrose)!
Good High GI foods?
Concerning individuals with normal bodily functions
(non-diabetics), there are times when a rapid increase in blood
sugar (and the corresponding increase in insulin) may be
desirable. Example: after strenuous physical activity, insulin
helps move glucose into muscle cells, where it can aid in tissue
repair. Due to this, some trainers and coaches recommend high-GI
foods (such as sports and recovery drinks) immediately after
exercise to speed recovery.
Also, it's not just the Glycemic Index that leads to the
increase in blood sugar. Equally important is the amount of the
food that you consume. The concept of Glycemic Index combined
with total amount intake is referred to as "Glycemic Load"(GL).
GL = GI/100 x Net Carbs
(Net Carbs are equal to the Total Carbohydrates minus Dietary
Fiber)
GI's of 55 or below are considered low, and 70 or above are
considered high. GL's of 10 or below are considered low, and 20
or above are considered high.
Conclusion, you can control your glycemic response by consuming
only low-GI foods and/or by restricting your intake of high GI
carbohydrates.
