What are the most important things to track?

To improve your health, track factors that have an impact on your RealAge, such as stress, sleep, smoking, diet and exercise. But if you're going to choose one thing, track your steps: More steps tend to lead to more healthy choices. I've found that when people track their steps, their weight tends to come down a little bit, and they choose healthier things to eat because they’ve just spent an hour walking around, and now they’re in a mindset that their activity is impacting their health. Conversely, I don't recommend tracking weight. It's so hard to change and people get hung up on it and frustrated when they miss their goals. With steps, you can hit your goal every day if you put your mind to it.