Whether or not cigarette smoking adversely effects bone density in adolescents is an important research question because it would also increase their risk for osteoporosis later in life.
Other important determinants of bone density are body weight, physical activity, hormones, and calcium intake.
In your opinion, which one/s of these factors (independent variables) will have a negative correlation with bone density and which one/s will have a positive correlation?
Please explain the reasoning for your answer.