1. Tray Information on FHIR

2. Use case and alternates
As a Nurse at a hospital in an acute setting, when caring for a patient who has Diabetes I need to know how many grams of carbohydrates they consumed at Lunch so I know how much Insulin to administer.
Alternate Cases:
I may want to know about the tray(s) and the foods that they will receive prior to them being delivered.
I may want to know the tray(s) and the foods that they were delivered.
I may want to review the food items on the patient tray and estimate intake so I can learn about the consumed quantities’ and Carbohydrate Grams

3. Which trays?
Which trays should be provided to the Nurse? Is there a code-able representation of a Meal, or do we want to know a timeframe?
Before we can provide information about a tray, the tray needs to be requested
The request needs to be authenticated
The request needs to ask for the patient they are requesting tray information for
The request needs to ask for a date
The request can ask for the datetime (all trays after that datetime)
Alt:The request needs to ask for a datetime range - all trays between
Meals are likely not sufficient unless this is a codeable entity
Also we can have more than one tray event for the same patient in the same meal period 

4. How should we present the tray information?
Tray Information: When there is a tray for the requested criteria we need to be able to provide the tray information in a usable format
We need to be able to provide information about the patient that the tray is for
Reference to the patient
We need to provide information about the status of the tray (ordered, delivered, consumed)
We need to provide information about when patient received the tray
We need to provide information if the tray delivery time is actual or estimated
We need to provide information if tray intake was performed
We need to provide which role performed tray intake - dietary or nursing
We need to provide the food items and associated nutrition that was on the tray
Food Item: ID (internal id), Food Name, Portion Description, Quantity, Intake Percent, Consumed Quantity (qty*intake percentage)
List of Nutrient Information: Nutrient Internal id, Nutrient (codeable entity, snomed code, GS1/GDSN), Shortname, Unit, per portion item value, Alt: Consumed Qty (per portion item value * qty * intake percent)