For today’s edition of Dear Mark, we’ve got four questions and four answers. First up, there’s a new whole grain study, and some people are claiming it demonstrates that low-carb diets will lead to early mortality. Does it do anything of the sort, or is this yet another flawed observational paper? Next, a teen on top of his diet game who hopes he’s doing it right writes in with a list of questions. I answer them. Next, what can a person recovering from a broken leg do in the way of sprinting? Or should she just focus on recovery? Finally, a wild and free man is roaming California with three pack mules, flouting convention and leading a nomadic existence. Police are occasionally called and media attention is often attracted. What are my thoughts?