I am a Chinese male who currently weighs 60.3 kg.
Based on the digital readout on the machine at my gym, for a male of my height, I am very much in the underweight zone.
But I eat Chinese food every day.
It’s a right mind boggler, hey?
How can I be Chinese, eat Chinese food every day YET still be underweight?
Well, I guess this is the part where I furnish you with some help.
The best way to answer your question might be to do a simple comparison.
This is what you think I eat for my meals:

This is the food I had delivered to my studio for lunch.
It cost 38 yuan (approximately 5.24 USD)
Inside the takeout lunch box, there is:
(top to bottom, left to right)
清蒸鲳鱼 (qīngzhēng chāng yú) [Steamed Pomfret]
香菇蒸滑鸡 (xiānggū zhēng huá jī) [Steamed Chicken with Shiitake Mushrooms]
芥兰 (jiè lán) [Kailan]

On the weekends, I have the time and inclination to cook one or two meals at home.
For this meal, there is:
(top to bottom, left to right)
清炒苦瓜 (qīng chǎo kǔguā) [Stir-Fried Bitter Melon]
西红柿炒鸡蛋 (xīhóngshì chǎo jīdàn) [Scrambled Eggs with Tomatoes]
小炒鸡丁肉 (xiǎochǎo jī dīng ròu) [Stir-Fried Diced Chicken]
Sometimes I prepare soup, but not always.

Hope this side-by-side — or is that top-to-bottom — comparison serves as an answer to your question。
I hope the week has been treating you well!
Have a wonderful weekend ahead!
Another answer:
Ok I’m not Chinese and other answers have tackled the “that’s not what chinese people eat” argument, which is solid and 100% true. But I do have something to add on how anyone can eat any type of food and still reduce weight.
I recently gained a lot of weight, over 10 KG going from 70 kg to 80+kg. I was eating nutella, tons of popcorn, eggs and rice for breakfast, oreo cookies, and my usual lunch/dinner with a meat, rice and veggies.
Some point after hitting 80 kg and seeing how my body had changed dramatically in ways I didn’t like, I decided to lose weight. I lost 4 kilos in a month and a half.
What do I eat now? Still nutella, popcorn, eggs and rice for breakfast, oreo cookies and my usual lunch/dinner.
What’s the difference? Reduced portion sizes. That’s it, that’s all you need to do to lose weight or maintain it. Instead of eating 4 packs of oreo a day, I reduce to 1 or maybe 1 every other day, same with nutella, same with chips (which I failed to mention before but are a vital part of my diet), I reduced from 3–4 eggs breakfast to 1 egg and a smaller portion of rice, if I know it will be a slow day I just skip breakfast altogether. I keep my same lunch/dinner menu but I serve myself smaller portions.
IMHO the easiest way to reduce weight, is to keep your EXACT same diet as before but reduce how much of it you intake. Changing what you eat is hard, but reducing it is way way easier. I don’t have to spend more time cooking, in fact I have to cook less, clean less, wash less. I do less effort to reduce weight than to gain it.
It took me about 3 days to adjust to the new normal with less food than before. Those 3 days are hard, after that it’s a breeze and you have to do less than before.
So what’s the “secret” (not a secret, it’s widely known and backed up by science) of eating anything without gaining weight? You just eat what you actually need, not more.