Glycemic Index vs. Insulin Load

The GI Trap

The Glycemic Index (GI) measures how fast a food spikes blood sugar. While useful, it ignores a critical factor: Insulin Response. A food can have a low GI (doesn't spike sugar) but still cause a massive release of insulin.

The Dairy Paradox

Dairy proteins (Whey/Casein) are the prime example. They have a very low GI because they contain little sugar. However, certain amino acids in them (Leucine) are highly insulinogenic.

This means a "Low Carb" protein shake can still spike insulin just as high as white bread. If your goal is ketosis or fasting (keeping insulin near zero), avoiding high "Insulin Load" foods is just as important as avoiding carbs.