The first seven
1. Don't eat dead white bread.
2. Never do "TV marathon". Best if you don't have a television in the first place.
3. Avoid obesity! BMI can be an indicator to help.
4. Keep your teeth clean.
5. Always wash your hands proper. Of course, don't overdo it or become obsessive.
6. Be slim
7. Stay away from alcohol. Never or if at all only moderate consumption.
... and 101 is always: Be happy and have fun in life!!!