Some people get old very earlier than they are supposed to be old from, it may be due to many different reasons but in most cases these habits were behind it:
1) Depression: If you are too depressed about something then you will get older earlier and you may also die earlier. Depression is another word for slow poison as it kills you from within.
2) Sugar: If you consume sweets and sugar too much than you are more near to death than you might think. It may cause diabetes and may create other health issues.
3) Sleep: If you are not getting proper sleep then you are not utilizing your hours rather you are decreasing your life.
4) No Exercise: If you do not have any physical activity then you will face many health issues of old people at a younger age.
5) Unhygienic Food: If you are not careful about your food then you might be reducing your life.