go to any standard sidewalk eatery and watch them prepare the dishes. a nice way of putting it is that hygiene here is really just a greeting to a man named Jean.
also go to a wet market and watch the butchers at work. that usually makes most people want to eat less food here.
also, being too cheap by nature keeps me from splurging for western food.

Since I moved to China, almsot two years ago, I have lost at least 10 kilos of weigth, going from a 40+ waist to a 36 now.

What have I done?  Well, nothing too drastic, mostly eat without salt, lots of veggies, hardly no fried foods (no oil used to cook), and as many Chinese do, walk a lot.  At first I could not walk too much, but slowly my stamina increased, and now I can keep up with many locals.  And another trick I use sometimes is to go up to my apartment using the stairs instead of the elevator (or lift), it does help to keep me in shape.

In a way,nd after some time here, I came to realize that eating Chinese food is a way for me not to eat as much food as when I eat western type.  I do feel fuller with Chinese food faster.

eat chinese food, rice makes you feel full but isnt as fattening as potatoes and fried western foods. Also if you try to keep your budget low and dont eat in western places then the food that you gnerally will get at cheaper places will be more vegetables and rice than meats.

Eat like the locals, dont drink too much beer... which is pretty much exactly what many of us dont follow.

Or, buy a bike and take to the countryside on the weekends.

Don't fill up on rice.

Simple rule - to lose weight, energy output must be higher than energy input! ('energy' meaning slightly different things, depending on context).

Easy answer - lots of vegies, lots of exercise (well, more than you've been doing...).

Losing weight is actually really easy... just takes a little bit of discipline.

Stay away from the noodles

Move ur ass and shut up ur mouth.
Do more sports and eat less...

I was 105kg (36-37 inch waist) about 5 years ago and slowly lost weight till I got down to 86-87kg (33") range. I eat well both in China and Australia and eat mainly Chinese style food. When I lost weight initially I did it by not drinking soft drink, cutting out desert and cakes, biscuits etc. I find in China I snack a lot more but keep my weight down by walking everywhere I can and using the communal exercise equipment that is in most parks and neighbourhoods in China.  

Eat street food exclusivley for a few weeks and you will be garunteed to get a massive bout of food poisening, thus you should shed about 10 pounds in 3 days.
But in all seriousness, if you can find a way here to regularily excersice (I mean really work-out), then your diet should matter far less.

eat smaller meals more often, filled with low fat protein and fiber rich veggies, to pump up your metabolism. Fruits are good in moderation, but don't over do because they have natural sugar. Stay away from sugars, rice, noodles, most oils. Olive oil is healthy, and a lil is good for your.. poopies.

Walk or ride your bike instead of public transport; stairs instead of elevator and work on gaining muscle tone to eat  the fat.

You'll be svelt in no time.