Why is my body changing since I moved to China?

2 things climate and diet.

The air in china can be very dry at times. In Beijing at winter time my skin becomes very dry as well.

As for you oder and spots, the odds are you get eating Chinese food more. Chinese food can be at times very oily and is full of spices like garlic etc. The oil in the food will cause your spots to be worse and the chemicals in the s spices will fuse out of you skin then you sweat.

Must be the water. I lived in San Diego, then went to Upstate NY. The water is very different. I then went to Guangzhou, China for 6 months. In China I noticed my Hair was different. Starting to fall out! Food, Climate, water can all have changes on you.

I think it's due to the environment. From water, to weather to what you consume. All these does play a roll.
Just try to adapt. Drink clean water, shower and wash your hair with filtered water perhaps. Wash your face with mineral water...and drink mineral water. Use body spray, etc.

Polluted air and strange food.

you're experiencing climate shock for what is happening to your hair, acne and body odor
it seems that you find it hard to adapt to your new environment

Yes, things in China are different from home (I am from Canada, too).

Hair - the difference between hard and soft water. We have soft water in Canada (hence, you find soap and shampoo lather up more easily here). The water in China is hard water, which can result in hard water deposits in your hair. Some people suggest rising your hair with water and a little bit of lemon juice after shampooing. Some suggest baking soda.

Acne - the environment (mainly oil, dust, etc.) Compared to back home, there are more pollutants in the air in China. This creates stress on your skin, together with stress on your body (ie. diet) due to being in a different place, you will find your skin more susceptible to clogged pores, etc. I am not a big skin care person, so I don't know what facial products to recommend, but rather, try to keep your face clean and keep your body/skin hydrated. Also, instead of using soap/facial cleanser all the time, try just rinsing your face with water. The more products you use, the more irritated your skin will be and the worse the acne problem.

Odor - it's because of your diet. Back home, you're probably noticed that the natural body odor of a Chinese is different than that of an East Indian, who also smells different from a Caucasian. It's mainly because of their diet.

probably all the soot from coal power plants and stuff...

dry hair -- because of the water...
something is added to it and if you wash your hair daily, the result is inevitable...
my way out -- bottled water, those big bottles for 5 gallons... for drinking, tooth brushing and hair washing... when i'm having a shower i hide my hair under a bath hat...

acne -- because of local spices, all those peppers, MSG, etc and geasy stuff, all those deep-fry, stir-fry, fry-fry etc...
no way to avoid if you eat outside...
my way out -- i cook for myself... trouble to expect -- weekly shopping, bags and packages, "daily slavery in the kitchen"... well, as good points i'm not getting fatter, don't miss my homeland cuisine and learn many new cooking skills...

odor -- eating and cosmetics... no idea what you use for hygiene but all local odors are kinda strange for me... even Nivea... i found some local aloe soap and i use nothing else...it's also essential to put your clothes and blankets outside (balcony or special drying planks under the window) otherwise some moisture bacterias can live there and make unusual smell even if the cloth seems fine... somehow they are invisible but highly aromatic...

The possible reasons for the change:
1. water qualities are different;
2. climates are different;
3. intakes you are now having are changed.

It will take a little for your body to adjust and get used to the new environment.

Because your trophic structure changed, just do this:
1、Drink some honey before you sleep.
2、Drink more tea. Tea contains a variety of trace elements, helps to reduce the acne.
3、Eat more fruits and vegetables and crude fiber food; drink plenty of water.
4、As far as possible to maintain the previous living habits.
This is chinese method to treat your situation,and wish to be helpful for you.