I travel a fair amount,
If you have a good expense policy: egg white omlet with lots of veggie for breakfast with side of fruit, water bottle. no carbs. great way to start day. in london, its often served with salad

or starbucks has a few good options: spinach egg white, large water bottle (or 2 water bottles),can add fruit cup, also consider protein plate.
i work with people that travel all their lives, at dinner, they always go with fish prepared simply, veggies, no dessert, reasonable appetizer (but doesn't need to be salad, can be the smaller splurge), no bread, lots of water. 1-2 glasses of red wine

I'm not 100% on this but try my best.
lunch - if they have sandwiches, cut the bread. i'm not a no carb person, but reducing helps. no dessert
bring small size protein bars (you can find brands in 1/2 size), for that "I'm starving moment". If you can, swing by pharmacy or something to buy extra waters.
try to always book your hotel with a good gym - plan on getting up early as most gyms fill up by 6 am