At the bottom of the tracker is a blue link that says "add daily note". You can't put notes by meal, but can put notes for the whole day in that area.
You can add additional meal categories if you'd like for your snacks. Those will go at the bottom of the Nutrition Tracker under the breakfast/lunch/dinner categories.
Hope that helps,
"You may have a fresh start any moment you choose, for this thing that we call "failure" is not the falling down but the staying down." Mary Pickford
"No matter how slow you go, you are still lapping everybody on the couch."