According to the bmi chart, under what category do you fall? why is bmi not always the best indicator of overall health?

BMI only measures height and weight, not muscle mass. So a person with a lot of muscle could be classified as overweight when in reality they are actually very healthy.

Primary effectit is the most accurate.

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