If I ate more than I would normally for a week, by this I mean eating 1000 calories of 'junk' everyday on top of my daily food intake, would I put on weight if I still exercised everyday by running for 25 minutes on a treadmill.

If I did put on weight, would I lose it by keeping up my activity level and going back to my usual eating habits?

How about if I did no exercise, and exceeded my caloric intake by 1000 calories for a week, would I put on weight and would I lose it again and go back to my previous weight if I started exercising again and eating as normal?

I really want to know the answer to these questions as I am always REALLY worried about over eating with bad stuff. I am not going to try it out, but it would put my mind at ease if I knew the answers.

Thank you very much.