Answer:
Alcohol
Explanation: Alcohol in moderation isn't bad but when one starts drinking heavily it can be detrimental to one's health
DNA Sequencing or genetics in general
Answer:
HIV is a virus that weakens the body's immune system, which is passed through blood, semen, or vaginal fluids. Ex: Sex, sharing needles. Its not curable, but with proper medical care it can be controlled. Poor treatment of HIV can cause AIDS, aka, stage 3 HIV.
This is not a good plan because it does not include healthy eating and exercise.