Question: Among the Yelp_Businesses which are still running, how many of them fall under the category of "Food"?
SQL: SELECT COUNT(T3.business_id) FROM Categories AS T1 INNER JOIN Business_Categories AS T2 ON T1.category_id = T2.category_id INNER JOIN Business AS T3 ON T2.business_id = T3.business_id INNER JOIN Tips AS T4 ON T3.business_id = T4.business_id WHERE T1.category_name LIKE 'Food' AND T3.active LIKE 'TRUE'