Pasting foods should append them to the end of the list
On Android, if you go through the somewhat complicated flow to copy a food from yesterday to today, that item may be pasted somewhere in the middle of today's list. My hunch is that the timestamp you had the food at yesterday is copied along with the item, and that determines the sort order for today.
That's strange - if I had a snack yesterday morning and I want to paste it this evening, it will show up instead this morning.
Note that I don't have Gold; by "morning" and "evening" I mean the first and last foods in today's list.
If unclear, the screencast may help.