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

Context: Five weeks ago , when he was born , he weighed 8 pounds 9 ounces and after that dipped down to 7 pounds 9 ounces . He has certainly been doing a lot of growing and all that eating has paid off for him . He also gained 2 inches and is now 23 inches long .

Answer:

He has an appetite now .



What may be a reason why he gained weight ?