Just about any ? one would have about eggs can be answered at http://www.aeb.org/

the american egg board

I think that for egg whites the dried canned egg whites would be safe, I am not certain about the nutrition but I do not think they have additives (such as 'Just Whites') I know when I want a quick 'dessertish' treat I whip some up and sweeten with stevia , a little honey, & flavoring, or have used other non TSP sweeteners (I wouldn't serve it to guests either -- not terribly clever ) and to be an approved TSP snack it would have to include other things-- but it works for me sometime , is fast, & protien.