that the essential cause of obesity is overeating is so well established that it seems hardly necesary to point out that the effective, safe mefhod for taking off excess poundage is to reduce food consumption.

밑줄친 부분에서 두개의 is중 어디가 본동사인가요?? is가 연달아 나오는데 어떻게 해야 할지 모르겠어요 ㅠㅠ