Net Carb = Net carbohydrate
Total carbohydrate (Sugars, Starch & other Polysaccharides) minus Dietary fiber. This gives the total carbohydrates that the human body can digest.

Gi# = Glycemic Index
Glycemic Index of food gives the rate conversion to glucose within the human body. GI uses a scale of 0 to 100, with higher values given to foods that cause the most rapid rise in blood sugar. Pure glucose serves as a reference point, and is given a Glycemic Index (GI) of 100.
While many sweet and sugary foods do have high GI's, some starchy foods like potatoes or white bread score even higher than honey or table sugar (sucrose) GI's of 55 or below are considered low, and 70 or above are considered high
The theory behind the Glycemic Index is simply to minimize insulin-related problems by identifying and avoiding foods that have the greatest effect on your blood sugar.
Your body performs best when your blood sugar is kept relatively constant. If your blood sugar drops too low, you become lethargic and/or experience increased hunger. And if it goes too high, body will convert the excess sugar to stored fat. greater the rate of increase in your blood sugar, body will release an excess amount of insulin, and drive your blood sugar back down too low.
Therefore, when you eat foods that cause a large and rapid glycemic response, you may feel an initial elevation in energy and mood as your blood sugar rises, but this is followed by a cycle of increased fat storage, lethargy, and more hunger!
Individuals with diabetes (diabetes mellitus, types 1 and 2) have an even worse problem. Their bodies inability to secrete or process insulin causes their blood sugar to rise too high, leading to a host of additional medical problems.

GL = Glycemic Load
Glycemic Load gives a relative indication of how much that serving of food is likely to increase your blood sugar levels.The Glycemic Load is the most practical way to apply the Glycemic Index to dieting, and is easily calculated by multiplying a food's Glycemic Index (as a percentage) by the number of net carbohydrates in a given serving.
GL = GI/100 x Net Carbs
As a rule of thumb, most nutritional experts consider Glycemic Loads below 10 to be "low", and Glycemic Loads above 20 to be "high".
Because Glycemic Load is related to the food's effect on blood sugar, low Glycemic Load meals are often recommended for diabetic control and weight loss. Please note that Glycemic Load is dependent on serving size.