If you are having them over for a visit in the afternoon (beween lunch & dinner) I would offer snack stuff. Chips w/ dip, fresh veg and/or fruit w/ dip, peanuts, pretzels, cheese & crackers & something to drink (beer, pop, tea and/or water). I don't feel comfertable having people over without having something even if small set-up. I ususally set it up in the dinning room or kitchen & entertain in the livingroom. If they are hungry they can move into the other room & snack.
It does take a little effort for me to cut up the cheese, fruit & veg (but that is because I buy the cheeper not cut up stuff, but you can get it pre-cut if you want to or even the pre-made trays.
We do have a family member that comes for holidays & she is anorexic. It is hard watching her interreact with her daughter (who is a size 5) and 2 grandkids. She will only eat 3 pc of cheese, a roll & catsup - even for Thanksgiving & Christmas dinner... and she loves to make comments about how much my kids eat and how much they weigh (they are only 2 - 32#, 4 - 35# & 5 - 46#). But in her eyes they are over wieght... her daughter can't believe everything my kids will eat - not the amount they eat, but what they are willing to eat and try. She always asks me how we got them to eat so many things... I always tell her, because they see us eating so many things. Her kids eat mainly what grandma does - which is why I'm saddened by her interreation with the little ones. I know she loves them, but she has already passed on her weight concerns to her dauhter - now she is working on the grandkids (mainly the granddaughter).
Please don't alter what you would normaly do for your company because of this woman... she needs to realize she is in the real world & most people do eat even if she doesn't. Sorry, I know it is a condition that is hard to overcome, but I wouldn't punish others because you are afraid of offeneding her.