List some of the side effects associated with tobacco use.

Lung,throat, mouth, kidney, and stomach cancer. Heart disease.

Because without physical activity, the body has extra "energy" if you will, and so when it is time for bed you are not tired, so you end up staying up all night. also there is probably an effect on your internal clock, which messes with your melatonin production which goes hand in hand with your sleep cycle

Behavioral science is the study of human behaviors and how they can be influenced.  by examining patterns in behavior as well as reactions, individuals with behavioral problems can be more adequately treated, resulting in greater mental health of our society/the public.