Do you have to brush your teeth twice a day even if you only eat once a day? assuming i brush after i eat and not when i wake up

Yes : Yes and wash behind your ears. It's healthier to brush twice a day...even if you only eat once (which could be unhealthy in itself). Bacteria tend to grow more on teeth why you not eating, saliva kills bacteria.

Actually: You need to floss once a day,brush your teeth and your tongue at least twice a day , and that is the minimum . Plaque buildup and acid formation continue weather you are eating once or more a day,also liquids consumption and other habits might contribute to that as well. Hope that help;)

Yup: Bacteria will stick to your teeth throughout the day, so it's best to brush twice a day to keep the plaque to a minimum. Your friends, co-workers, and close contacts will also appreciate your better smelling breath.

It is recommended: twice a day, but three times a day is the best. You should brush for at least 2 minutes, be gentle and use a soft toothbrush. Flossing twice per day is also recommended.