Not necessary at all, but not harmful either if those carbs are coming from sweet potatoes or berries. Best to keep you overall carb totals in mind, and not to exceed 150 grams by too much. I don't know why you'd eat sugar though, what really do you need to put sugar on? I'd just stick with the potatoes and fruit, just making sure not to go wild with it.
There is a pleasure in the pathless woods,
There is a rapture on the lonely shore,
There is society, where none intrudes,
By the deep sea, and music in its roar:
I love not man the less, but Nature more...