You mean like for medical reasons (e.g. gastrointestinal disease, anorexia, yadda yadda), or just because they are really really picky? More details, please!

Peanut butter and banana sandwich. I have a sister like that. Oh applesauce and cottage cheese she would eat also. And cookies I made oatmeal to try to get something good in her. I snuck some cooked squash into it long before Seinfeld even had children.

Tea and scones? Seriously though, what does this person eat? No veggies at all? What about fruits? Grains? Nuts?

A good, stiff drink and copies of all the local take-out menus. No way on God's green Earth would I cook for them.

Air is good. But you need special equipment for that.

Dietician, definitely.

I'd recommend a trip to a dietitian, or undertaker.

How about tofu, tempeh, seitan or polenta?

Roasted Peeps... ;-0

It seems quinoa may be the healthiest thing this person would eat. I'd go for lots of whole grain bread, fresh fruit, and nuts. One of my sisters-in-law pretty much subsists on those, along with certain veggies.

On another note, have you looked into Selective Eating Disorder?
http://en.wikipedia.org/wiki/Selective_eating_disorder

I know it sounds a little wacky, but my sister-in-law has made me a believer.

Is there anything this person does eat?