At the beginning of my journey about
four years ago into measuring my blood sugar as a diabetic, I thought it was fairly simple to avoid sugar and my blood sugar would be fine. Was I ever wrong! It's the carbohydrates, no matter from what source. Yes, there are fast-acting and slow-response carbs but carbs will be carbs and carbs will raise blood sugar. Eat a head of cauliflower and your blood sugar will rise. Since all of us will have different reactions to them, that is, how many carbs it takes to raise our blood sugar how many points, we need to understand how our own bodies metabolize them and keeping a food/blood sugar journal is a good idea.
Sugar-free cake and cookies? I fell for that one in the beginning and saw my blood sugar rise. Flour! Put flour, even whole wheat or whole berry, into anything and we will see higher blood sugar. Yes, it might take longer for the rise if the bread slice is whole wheat but flour means carbs. Check the food packages' Nutrition Facts for Total Carb. The higher the number, the higher your blood sugar will rise.
Sugar substitutes? As I pointed out in another thread today, Splenda, Equal, etc. and even stevia products do have some small degree of carbs, so if you're counting carbs, don't forget that. Milk = carbs. Coffee with artificial sweetener and milk = more carbs. The flavored coffee creamers have even more.
However, just being a sweet person, doesn't raise anyone's blood sugar as far as I know. 