Vienna, Prague, Berlin + Amsterdam....

ohh have fun! In Amsterdam they'll have plenty of choices for you, there's a large variety of restaurants to choose from though if you don't want to eat fattening food, I'd really recommend staying away from Dutch restaurants. The ones that are really expensive are probably better for your waist but not so much for your wallet!

In Holland you will find a couple of things a lot: (read; in almost every street/cafe/restaurant)
fries (topped with mayo or peanut sauce, abt 800 calories per portion.. oops) fish stands, but usually except for herring which is VERY healthy and I would recommend, the rest is fried in batter. Dutch pancakes, poffertjes, apple pie and food you van get out of the wall. Also avoid the 'wall food'. Almost everything is fried, very processed, and fattening, especially the 'frikandel'. And then to think most people also smother these in mayo and curry... anyway!

Things I can recommend to you that are worth trying, (pretty) safe, and not very expensive, are these;
herring (and eat 'em the traditional way!) very fresh and in season right now.
From the 'out of the wall food', you can try the kroket (usually around 140kcal, 6gr fat, which isn't too bad!) or it's round variety which you can also order at many cafes, 'bitterballen'. Usually served in portions of 5-10 and contain about 35-40kcal per ball (size of your palm)
Certain shops also have pretty good and fresh banquettes/sandwiches, fruit salads, or smoothies. I really like going to la place (which is part of the V&D department store) they usually have a to-go section and a restaurant where you can sit down inside. They can offer anything from regular, hawaii or italian burgers, pizza bread, salads and soups in their restaurant, and their to-go section has some very tasty paninis and sandwiches (a good choice is the mexican chicken one which has a raw, fresh tomato salsa!) at reasonable price Delifrance is also good, and I'd recommend Dutch cheese as well (still remains the best for me. But maybe I'm biased because I'm dutch!) you have reduced fat and salt cheeses but if you order a little platter somewhere with mustard it;s not going to add up too bad.
Also greek and italian restaurants are usually pretty good around here. Also some seafood restaurants! It's best to stay away from Chinese restaurants as well as the small turkish take-outs. Indonesian and Surinam food is also a good choice!

The sweet stuff;
Dutch pancakes - they usually contain less fat than their american counter parts, and are larger and thinner. You can top them with anything you like, from fruits to syrup or even have them cooked with a little liquor!
Little note: STAY AWAY from the smaller round ones called poffertjes. That's nothing but a bite of wheat in butter.

Caramel waffles/stroopwafels - go for the fresh warm ones Average sized waffles are around 120-140cals and are very thin. If you buy the fresh ones at the market you can usually also buy the crumbled variety which has less to no caramel and can save you calories.

Dutch apple pie is also not too bad; if you don't top it with the whipped cream! It's definitely better than cheese or mousse cakes.

Some other general rules of thumb; avoid any dish that contains 'spek' (worse than bacon) don't get 'rookworst' (saaaallttt lots of trans fat), avoid most schnitzels (fried), don't get saucijzen/kaasbroodjes (filled with fatty meats and cheeses..)
Look out for these lean options if you see them; ham is usually pretty lean meat around here, 'tartaar'/tartar which is very, very lean beef usually served on bread with onions, a less rough variety on this is filet americain (only opt for this choice at decent bakeries/butchers/market stalls specializing in beef), smoked fish, etc. Hope this helped you