What is the Number
Glycemic Index (GI) is not a measure of sugar quantity in food. It is a measure of the speed at which blood sugar rises after consuming it. The difference between 'how much' and 'how fast' is the core of the subject.
Glucose is the reference standard at 100. All other foods are ranked below it.
The Scale from 0 to 100
The scale is divided into three clear zones. The lower the number, the slower and gentler the rise in blood sugar:
Why Two Foods Differ
Five factors govern blood sugar rise speed:
1. Type of Starch: Amylose digests slowly, while amylopectin digests quickly. Long-grain Basmati rice is high in amylose, hence lower in GI.
2. Fiber: Fiber slows down everything — starch digestion and sugar absorption. Hence whole wheat bread has lower GI than white bread.
3. Fat & Protein: They slow down gastric emptying. Pair a date with nuts to lower the glycemic impact.
4. Ripeness: A green banana has a GI of 30, while a ripe one jumps to 62 as starch turns into simple sugars.
5. Cooking Method: Al dente pasta is lower in GI than overcooked pasta. Cooling cooked rice or potatoes creates 'resistant starch' which digests slower.
Saudi Foods in the Scale
The Crucial Difference: Index vs Load
Glycemic Index measures speed only. Glycemic Load (GL) measures speed + quantity. This explains why watermelon is safe for diabetics in moderate amounts, despite its high GI of 72. A serving has very little carbs because it is mostly water.
Glycemic Load Calculator
Four Practical Rules
Build the Plate, Don't Isolate
Add protein, healthy fats, and fiber to any starch. Pair dates with nuts, and rice with vegetables and lean meat.
Focus on Load, Not Just Index
Quantity matters. A cup of watermelon has a low load, while a massive plate of rice has a high load.
Prefer Whole Foods
Whole grains over flour, whole fruit over juice. One step closer to nature decreases GI naturally.
Use Cook Tricks
Cool cooked rice/potatoes and reheat to increase resistant starch, cook pasta al dente, and use lemon/vinegar.