To be happy and healthy you need to find a good balence. A little bit of everything in moderation. Not just talking about food here, although it does apply. I am talking about, if you work hard, you need to play hard, and you need to make sure you have enough sleep. It is important to make an effort to spend time with friends and family. If you are always too tired to see friends then something in your life is out of wack! Take a step back and have a good look at what you do day in day out. Each week should consist of work, physical activity that you enjoy, quality time with loved ones and a catch up with some friends. A good mixed diet full of lovely colours will also help in the health department. Leisure activities are also important to take us away from the daily grind. Having a little bit of a treat, like chocolate cake or wine, is also fine.
Like i said it is all about balence, but we do have to sometimes push ourselves to enjoy a bit of the good stuff, but my, when we do, we certainly appreciate what we have.