Tolstoy wrote this list of rules for happiness when he was 18.
Well, I don't eat sweets, or too much generally, so that has to be a start I guess...
Get up early (five o’clock)
Go to bed early (nine to ten o’clock)
Eat little and avoid sweets
Try to do everything by yourself
Have a goal for your whole life, a goal for one section of your life, a goal for a shorter period and a goal for the year; a goal for every month, a goal for every week, a goal for every day, a goal for every hour and for evry minute, and sacrifice the lesser goal to the greater
Keep away from women
Kill desire by work
Be good, but try to let no one know it
Always live less expensively than you might
Change nothing in your style of living even if you become ten times richer
I always preferred Dostoyevsky anyway.