B) engaging in a fun physical activity on a regular basis
it may be a medical problem but you yourself said you have poor eating habits and the can 100% cause weight gain. A burger fry and a drink is about your supposed daily intake. Eat right see if it help's otherwise go into a family/general/internist doc and get some test done.
Yes that is correct
Specific
Measurable
Attainable
Realistic and
Time
I think you get it at 13 I think I think