Based on the context and the answer, generate a question. 

Context: I just do n't know if I want to do it before or after lunch . I feel I could go either way ... but they might tell me to go eat lunch ... but I feel I 'll be too lazy to eat lunch and then go back to donate blood . Soo ... let 's hope it works .

Answer:

He may pass out if he does n't .



Why may they tell him to go eat lunch ?