Reactions - let's talk about them for a while...

Well when I am talking about some food if it should be eaten or not here on forum or anywhere we talk about candida, people often tell me "well try that food and see how you react to that". Well, I don't understand that, since I never have any reaction of food I shouldn't eat. What I am trying to say is that I could probably eat Sugar and yeast right now whatever I want and I would probably not have any direct reaction from that, but of course that would feed candida so I will not do that heh. On other side I have reactions when I eat some food that I can and should eat like garlic, and probiotic yogurt... but I guess that is ok since it's probably because die off...
So I would like to hear about you: do you have any reactions if you eat something that is not on diet menu and how fast it happens after you ate it, and on other side is it normal to have reaction (if I can call only bloating and very small stomack pain) approximatelly half or full hour after you took some garlic, or probiotics etc...
I think it nice question since we should all know do differ bad reaction (reaction if you ate something you shouldn't) or good reaction (if it's because of die off). How to be sure it's one of those two. I'm afraid that maybe bloating I have immidiatelly after eating probiotic yogurt is maybe not from die-off, can it also be because of fructose or natural Sugar in yougurt? so want to clear this up - let's talk about those reactions for a while...