Interesting question. Just today came back to Toronto. Checked off "no" for food on Canadian customs form. When they asked me how much in goods I brought back (considered a resident because of my work pemit) I answered $150. When they asked me what I had, I answered chocolates, shirt, socks, candy, cereal... She wrote next to the box where I checked 'no': chocolates/ cereal OK and sent me through, no inspection needed.

I have checked off no for food at Toronto-Pearson (without thinking) and brought a piece of fruit which I ate before departure. No harm, but maybe if there's a $10,000 fine I better not try this again.