Glycemic Index: How Foods Affect Blood Sugar

The Glycemic Index (GI) ranks carbohydrate foods (0–100) by how rapidly they raise blood glucose compared to pure glucose (GI=100).

Categories

• Low GI (≤55): Slow digestion/absorption → gradual glucose rise. Examples: steel-cut oats, legumes, most fruits, non-starchy vegetables, nuts.
• Medium GI (56–69): Basmati rice, whole wheat bread, sweet potato.
• High GI (≥70): Rapid spike. White bread, cornflakes, instant rice, potatoes, glucose drinks.

Glycemic Load (GL)

GI × carb grams per serving / 100. Better reflects real-world impact. Watermelon has high GI but low GL (few carbs/serving).

Health Implications

• Low GI/GL diets associate with ↓ T2DM, CVD, obesity, some cancers.
• Improves glycemic control, satiety, lipid profile.
• Not a standalone diet—context matters (fiber, fat, protein, processing, ripeness, cooking method all modify GI).

Practical Tips

• Choose intact whole grains over flour-based.
• Pair carbs with protein/fat/fiber (e.g., apple + peanut butter).
• Cool cooked starches (potatoes, pasta, rice) → resistant starch → lower GI.
• Don't avoid nutritious high-GI foods (e.g., carrots, watermelon) based on GI alone.

GI is a tool, not a diet. Overall dietary pattern matters more.