Hi there!! If you choose to eat less food, it is OK to cut out the grissini toast and a fruit or so.....but always try to get in your protein to prevent developing protein deficiency and then losing muscle mass. You should try to get as close to 500 calories as possible, It is a subsistance level as it is and you don't want to stress your system any more than it already is. Hope this helps, and welcome to the forum. :))
Protocol says if you are not hungry that you can leave out anything you want as long as you get the protein in. If you do that though make sure you are getting your vitamins. I would not recommend dropping the veggie as you need the nutrients from it.