Replace decay with rate

[Kalhama]

I think it's more beneficial to report rate than decay time because decay is dependent variable of meal size and rate, and rate is dependent on the glycemic index of the meal.

• Ultra high GI: ~100g/h, such as plain sugar or fructose (candy, soft drinks...)
• High GI: ~40-60g/h, high GI carbs such as potatoes, rice
• Medium GI: ~30g/h, complex carbs, or high GI combined with balancing elements such as high protein, fat, fiber. Also base rate for high GI carbs after enzymes get exhausted.
• Low GI: ~20g/h, protein, fat

This also mentally encourages splitting meal by the GI type. When you don't know the combined GI just input two meals.