My advice is if you're working for someone else, work as much as you're paid. In your spare time start a project to make money for yourself. And always remember, there is more to life than work and you'll never get time back so no regrets (just learning experiences).
I've started working from one day a week and have found I can get significantly more done away from the office. Maybe going into work a couple hours before others would help too...
Again, body mass index is only a valid measurement if you know you're unhealthy (plenty of people are "athletic" but BMI tells them they're overweight). At that point, you don't need a semi-random telling you so. Body composition is a better measurement.
Seriously, one day we read an article saying a diet "near starvation" will help us live longer and the next we read "excess pounds" is the way to go. The key is doing everything in moderation.