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Low GI Diet

Eating a low GI diet means eating foods with a low Glycemic Index (GI) value rather than a high GI. GI is a measure of your blood glucose (sugar) level over a two hour period after food consumption.

The Glycemic Index rates the foods effects on blood sugar on a scale of 1 to 100, 1 being the lowest and 100 being the highest.

GI Category GI Range
Low GI Foods 55 or less
Moderate GI Foods 56-69
High GI Foods 70+

High GI foods spike your blood sugar levels more rapidly than low GI foods.

The following chart compares the spike in glucose during the course of a two hour period after eating a high and low glycemic food.

Low GI vs. High GI Chart

When your blood glucose is spiked, your brain signals for the secretion of the hormone insulin. Insulin transports the glucose out of the blood and into your muscle cells and fat cells.

As shown in the graph above, you can see the insulin causes a decrease in the amount of glucose in the blood after 30 minutes.

Low GI carbohydrates come from complex carbs (whole wheat bread) and high GI carbs are from simple carbohydrates (sugar). Complex carbs take longer to break down in to sugar resulting in a slow steady rise in blood glucose; in contrast, simple sugars are processed and digested quickly resulting a more drastic rise and fall in blood glucose over two hours.


Why A Low GI Diet Is Beneficial For Overall Health

Here are some of the general health benefits of adopting a low GI diet:
  • experience lower spikes in blood glucose (important for diabetics);
  • lowers your cholesterol;
  • improves insulin sensitivity;
  • reduces your risk of heart disease and diabetes by 50%; and
  • lowers insulin levels (high insulin levels is linked to heart disease and hypertension).
If you are a diabetic, you need be particularly aware that you need to consider the quantity of carbohydrate in the food, as well as the GI, this is known as the Glycemic Load.

Here's how to calculate the Glycemic Load:

Glycemic Load = Number of Carbohydrates (grams) GI 100


Low GI Diet Benefits For Weight Loss

Eating a low GI diet will help you lose weight by enabling you to eat more, without gaining more weight (due to low insulin production), and it reduces your hunger pangs (complex carbs makes you feel fuller over a longer period of time due to slower digestion of the food).


GI Levels For Athletes

Athletes need to consume complex carbohydrates (low GI foods) throughout the whole day. This will provide the athlete with the endurance and energy lasting for the entire game or practice. Simple carbohydrates (high GI food/beverage) do need to be consumed just before, during and after the games/practice to top up energy levels.

For more information see nutrition for athletes.


How Bodybuilders Can Manipulate Insulin Levels To Their Benefit

For those trying to build muscle, most of the time you will want low insulin levels to keep your bodyfat down.

However, weight trainers will want to increase their insulin levels (via eating high GI foods) before and after their weight training sessions, because it's at this time when the insulin is most likely going to transport the sugar and other muscle building nutrients (vitamins, anabolic hormones, creatine etc.) to the muscle cells rather than the fat cells. The higher amount of insulin means more nutrients hit the muscles, which then translates into more muscle growth.


How to Lower Blood Glucose After Eating High GI Foods

If for whatever reason you have to eat a high GI food you can minimize effects on your blood sugar by eating low GI food(s) with it.

Low GI foods you could eat with high GI foods are:
  • vegetables,
  • nuts, and
  • beans.
See this page for a list of more low glycemic foods.

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