Glad the thermos worked! That sounds great for Day 1..definitely eat if you are hungry, good move to get a bunless burger. The only thing missing (and you may have enough on your food) is salt. The cup of broth morning and afternoon prevented headaches and got me over that afternoon snack time.
Add a bouillon cube to hot water or eat some salt and wash down with water. Better to avoid "induction flu" than deal with it while working.

Here are ordering tips for a number of fast food restaurants. Be prepared for the times you aren't prepared. http://lowcarbdiets.about.com/od/ea...arbfastfood.htm