eat all the Ben and Jerry's you want
I doubt they eat all the ice cream they want and maintain 3% bodyfat.
Why would you be risking your health if you looked like that, I have been thin most of my life and I am much better off than all those good looking fat people. Thin does not mean unhealthy-you would think on a bike forum that fact would be a forgone conclusion.
Naturally thin is one thing. Having barely enough bodyfat to survive is another. At low body fat percentages various organs shut down like the brain and reproductive system.