I have seen many customers handle this in many ways. For example, some have a daily limit where an individual can't have more than a given amount (say $75) on meals throughout the day. This could change if the dinner had attendees where the expense could change to meal-attendees instead of individual meal. itemized receipts are typically required for these type of expenses.
Other clients have implemented a per diem policy where meals are paid for as long as they fall within a governmental allowed amount for that given city. Concur feeds in the GSA per diems on a daily basis for clients who need this service.