I am almost 17 and since i can remember i have usually pooped only once a week. I have not told my doctor, but i have never had any problems. I normally do not eat breakfast and i eat little to no lunches. I only exercise a couple days a week because of school work. I do drink large fruit smoothies which tend to make me go often but on 3 times a week and without them i go only about once every 7 days. Should i be worried? Thanks.