So you didn't get a response in 4 hours, so instead of bumping the thread, you post a snide remark? Real smooth, bro. FYI, some members don't get responses for 12+ hours. IN CASE YOU DIDN'T KNOW.
I'd suggest a 100mm f/2.8L Macro for Food Photography. You can get some wide shots (provided there is enough space), as well as some up close and personal detail shots. The other lens I'd look at is an 85mm f/1.8 (or Siggy 85mm f/1.4). Although, Charlie's on the right track when referencing a lot of lights and fat modifiers. That's what your friend really would need. And the knowledge to use them of course (which costs a lot more than the lights themselves)
A 50mm f/1.8 would be absolutely useless IMHO, especially the Canon variant. I'd use a 50mm f/1.4 if I had to, which wouldn't be a BAD lens, but wouldn't be ideal.