On the mobile app, tap the + button at the bottom right corner to add a new meal item instantly while sending a food update. This option is available only on mobile.
If you want to modify or delete existing meal items, go to Admin Tools → Tag Settings →Meal Items.
On the web version, you cannot add a new meal item directly while sending a food update. To add or modify meal items, go to Admin Tools → Tag Settings →Meal Items, make the changes, and save. The updated list will automatically reflect when you send your next update.