It is advised to brush your teeth at least twice a day, but when? Just before bed is a gimme because you're about to lie mostly still for 6+ hours. Best to not leave food particles to fester.
What's the best time for an earlier brushing? After breakfast? After lunch? After work/school?
Plus, what's up with TV and movies having breakfast scenes where they get up and head right out the door? Did they already brush and now they're going to leave food to fester all day? Eww.
That's true, but it's enough to just rinse your mouth with water before brushing your teeth to eliminate any acidity from the food, or just wait at least 30 minutes before brushing your teeth.
For breakfast if you drink milk and eat nothing acidic (like fruits) that would weaken the enamel, brushing after the meal is the best.
Also brushing your teeth does slightly damage your teeth, which salvia will repair. I don't want sugar in my slightly damaged teeth, nor do I want sugar on them for the rest of the day, until I brush in the evening. I like to extend the duration of brushed teeth to the maximum. Meaning over night clean and after breakfast, til often evening when I eat once more. With midday being all clean without extra brushing.