Hi all

I'm writing some diet/nutrition tracking software and would appreciate your
thoughts on something.  I'll keep it brief and get straight to the point.

The software maintains a database of foods which users can add to their
daily food log.  There's one of two ways I can program the 'adding' part:

- store a reference to the food and when the user needs to check the foods
eaten on a certain day, I can use the reference to look up the foods values
from the food database.  With this method, if the user edits the food
details (name, nutritional info, serving size etc) the details are also
updated in the food log because the info was never stored, just a reference
to it.

- copy all the information i need from the foods database into the food log
database, thereby having an independant copy. If the details for the
original food are changed, the details in the food log are preserved - they
don't change.

The advantage of using the first method is I can pull all kinds of useful
statistics, e.g. 'show me how many times I ate food x between date a and
date b' .  The disadvantage is the food needs to stay in the food database
for as long as you want it to appear in your foods logs.. deleteing the food
deletes it from the logs too.

I'm more inclined to use the first method, simply because I don't see the
harm in having a food stored in the food database indefinitly.  Each food
takes up only a tiny amount of space.

I'm looking more for usability rather than technical opinions.  If you use
diet or nutrition software, how does it handle deleteing foods.. are the
foods also purged from your food logs?  What seems to be the more
intuitive/natural behaviour?

any thoughts and input would be much appreciated
mark