“How many grams of sugar will spike insulin?”

If you are a counter of carbohydrates, know that there are about 4 cal per gram of a CHO (like sugar). There are also about 4 cal per gm of a protein (meat, fish, chicken, etc.) and 9 cal/gm of fats (oils, waxes, meat fat, dairy fat, etc.). There are only these three food/energy types. One can accurately learn to quickly estimate the caloric load of a meal or snack. By the way, alcohol, a separate category is, about 7cal/gm.
Hope this helps. See a diabetic educator for a class. Most hospitals and federally qualified health centers provide this type care for little or nothing.