dup dies of starvation with of 50,000kcals of food

Your available food is "Muckroot and Meal Lice."  Neither muckroot nor meal lice are acceptable food choices for your dupes.  This is not a bug.  Let your dupes eat the muckroot and meal lice and they won't starve.

Klei should really add a hint for this at the starvation alert (like "Visit the Consumables window to check if the duplicant is allowed to eat the available food"), because many players had this problem yet.

Edited April 21, 2018 by Queron81

In the next hotfix, the status item and notification message will now change to tell you that they cannot eat because of consumable permissions as opposed to not being able to reach their food. Thanks for reporting this!