17 to 18-year-old teens are starting a very exciting time in their lives. It is a time of increased independence and much more responsibility.
Diet and Nutrition
Your 17 to 18 -year-old teen is on the cusp of adulthood. They are making much more of their own decisions about food and nutrition. They could now be living away from home and you may have very little say in their food and nutritional decisions. Hopefully by now, they have developed healthy nutritional habits that will follow them through their adulthood. If your teen is living away from home, money can often be an obstacle when it comes to purchasing good food. Teach them how to make healthy food choices on a budget.
Sleep just doesn't appeal to most seventeen year olds, they want to stay up late and sleep in as late as possible. However, 17 to 18 year olds need their sleep to help them concentrate on exams and study so your job is to ensure they are staying on track, if you can. Put curfews in placeand ensure your teen knows that you expect him to meet these curfews.
It’s important to help your teen develop good exercise and fitness habits. Encourage them to stay active, teens should be getting an hour a day of physical exercise. 
17year-old teens can often be excited one minute and stressed the next. Their world is quickly changing; they are saying good-bye to secondary school and their friends and facing college or work life. It is certainly a challenging and stressful time.Parents can help their teens handle stress by working on building their confidence. Giving teens reminders of their abilities, listening to their ideas, allowing them to make their own decisions and offering them constant love and support is important.
Behaviours, Responsibilities and Discipline
Your 17 to 18-year old will have lots of responsibilities as they work towards achieving the results which will allow them to begin the next phase of their life. If your teen is finished school and still living at home then you will need to have groundrules in place to ensure a harmonious living environment.