Does anybody know how to change the activity level you chose when you created your account?

Just go back in to set your rdi and select your activity level again

What Johnny said. Go to your diet calender, where you enter your food, at the very bottom of that page you have the option to recalculate your RDI, and here is that option also. It's a great idea to recalculate every now and then regardless. As we lose weight, we burn less, and a new calculation is needed.