If have a small breakfast (maybe some almonds and a fruit), but without sugar, do you mark it as done?

Provided the breakfast gave me enough energy to get ready and I have an early lunch or brunch ahead, than yes.
But please remember that food is fuel for your body and try to make sure you have enough to keep your body and mind healthy.
This includes sugar as your brain requires sugar to fuel the synapses. I suggest a daily square of dark chocolate to keep sugar cravings away.