Can I Eat Oats Mixed Vanilla Protein Whilst Completing at Home Teeth Whitening?

I have been using 'Polanight' overnight 16% at home trays in an attempt to whiten my teeth. I have used them for the past 5 nights. In the first 2 days I ate Chicken/Turkey/White Fish, White Rice, Cottage Cheese, Milk and Egg whites. The past couple of days I have had Oats mixed with vanilla protein powder, is this okay to eat whilst completing this treatment?