How do I delete a food from a meal?

To delete a food you can do this by, "swiping left" over the item will bring up a red delete button and the item will vanish.

You can also edit entries, you don't have to delete and redo them. Just open the item, make the changes, scroll to the bottom and tap save. 

To delete from the food diary:
1) Tap the green arrow to the right of 'Today's totals' on the dashboard
2) On the Food diary screen use the arrows next to the date to scroll to the item you wish to edit. 
3) Swipe right, from the left of the screen over the item you wish to delete from the diary.