Invisalign: How to Eat when Can't Brush Right Away?

Ideally, one would brush after every meal, but not all people can.  The invisalign aligners can act as reservoirs and trap food and acids that would normally be washed away from saliva.  If one brushes and flosses well, morning and night, then things are likely going to be fine.  It takes roughly 8 hours to demineralize, so it should work out ok.

You should remove the aligners to eat and to
brush your teeth. If the aligners are not removed while eating it is suggested
that you brush your teeth and rinse the aligners immediately after eating.

Ideally, you want to brush and floss each time after you eat before you insert your aligners.  Realistically, that can't always happen.  Either rinsing your mouth with warm water or chewing sugarless gum for 20 minutes after a meal will help remove food particles and move them and the bacteria off your teeth.  If you need to reinsert your aligners after that, just brush and floss as soon as you can and make sure to clean your aligners as they probably picked up some of the particles from your last meal.