You can definitely get sued for copyrighted keywords.
Usually people will contact you though before filing suit.
Yes , Atkins is definitely one. But there are also ones which you would not suspect.
One way to find out is to type the word into a search engine and see what comes up.
Obviously I am not the best authority on how to avoid lawsuits based on trademark infringement. :laugh:
If in doubt, ask a lawyer is my policy now.