Read the following context and answer the 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 .
Question: Why may they tell him to go eat lunch ?
Answer:


He may pass out if he does n't .