It seems to me that there are two ways of looking at living a fit-lifestyle. Those that live unhealthy lifestyles usually have some combination of constant drugs, alcohol, tobacco, sedentariness or unhealthy eating in their life. For these people, the first step is to look towards lifestyle improvements and living healthily. This approach has a focus more on making improvements and enjoying them instead of worrying about specifics. This means eating right, but not worrying about caloric intake or doing a triathlon. Hosting a healthy lifestyle is a purpose without regard to calorie consumption or specific training methods. The first priority for those living unhealthily should be to get their life back on track and then get more specific.
You would never seem someone who just healed a broken bone go do The Ironman, so why would an unhealthy individual micro-manage their fitness aspirations? Instead, they should focus on improvements like:
- Eating fresh, local and organic food (produce, meat, whole-grains, etc)
- Drink lots of water (1 oz/pound of body weight)
- Exercise regularly (get some sort of exercise daily)
- Eliminate as many vices as possible (quit smoking, limit alcohol consumption, etc)