Perhaps you should try some spelling variations:
"cost of _ health diets" » "cost of _ healthy diets", "cost of _ health diet", "cost of _ health die", "cost of _ health dies", "cost of _ health diess"
"cost of _ healthy diet" » "cost of _ healthy die", "cost of _ healthy dies"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("cost of _ health diets") OR ("cost of _ healthy diet")).
• Removing quotes may allow a broader search: (( cost of _ health diets ) or ( cost of _ healthy diet )).
• Adding a wildcard symbol may retrieve word variants: (("cost of _ health diets") or ("cost of _ healthy diet"))*.