If you notice that the tongue has a normal red
colour after eating then your tongue
is now fine. The whiteness
will be caused from a dry mouth. I do know that a thick fury tongue (white or sometimes yellow) is an indication of stomach problems.
If your oral hygiene and your stomach and bowels are fine, you have nothing to worry about.
Just remember that anytime you have an antibiotic for whatever reason, you are now prone to getting oral thrush.