Context: Seph ate way more than I did , I doubted he could always eat like that and yet keep so skinny ... Both of us crept up the stairs and said goodnight to eachother . I settled down into my bed and tried to sleep . Rain lashed at the windows , and thunder shook the entire house .

Question: What may be the reason why they do n't think Seph will stay skinny ?
Options:
0. None of the above choices .
1. He is n't eating very healthy .
2. He is already getting a gut .
3. Metabolism slows down as you age .
Answer: 3