Tortoises are grazers. They need to be able to nibble all day long. If you are feeding the correct high fiber, high calcium type of foods to a well hydrated tortoise in a correctly sized, properly heated enclosure, then you should have no problems with over eating.
I too, like Jodie, feed mt beloved tort in the morning only, especially in Winter. Now it is extremely cold, and it's known that torts lose appetite when it's cold.