Database: allergy_1
Question: Find the number of male (sex is 'M') students who have some food type allery.
SQL: select count(*) from student where sex  =  "m" and stuid in (select stuid from has_allergy as t1 join allergy_type as t2 on t1.allergy  =  t2.allergy where t2.allergytype  =  "food")