We mostly eat rice as staple food. Normally, we eat steamed bread(mantou) and rice congee for breakfast. For lunch and dinner, we eat rice and other dishes, such as pork, vegetables, etc. That's only my experience. Things will be different for diferent people.
Personally, I like to eat stir-fried veges and meat with rice everyday. Sometimes we make stew with Chinese cabbage, spinach, tofu, rice noodles, meat and a few dried small shrimps. My mother makes the perfect stew. My grandparents prefer doubao (steamed buns stuffed with sweetened bean paste) instead of rice. We make dumplings twice a week. We cook pork rips or chickens or fish at least once a week. Sometimes we would buy fried chickens or roast chickens to satisfy our cravings for calories. We make rice soup every evening and soy milk every morning. We have bread or deep-fried dough sticks in the morning. We buy all kinds of snacks really often: chips, sweets, cookies, pastries, sausages... Oh right, fruits. It's summer, so now we're eating watermelons everyday. My whole family are foodies! We eat a lot everyday. I know it doesn't sound healthy, but our diet contains a lot of vegetables and eating is good for your mental health. My grandparents are both over 80 and they're still healthy.
China is a very big country, so we eat different food at different parts of our country. It is said that there are eight 菜系, eight styles of food in our country, namely Cantonese, Sichuan, Anhui, Shandong, Fujian, Jiangsu, Hunan, and Zhejiang food. But of course there are also some minor styles which are not included in these eight. I know the most about Cantonese food, and the most famous Cantonese food is dim sum.
If you are not looking for an detailed academic research but an idea of what Chinese people eat, it really depends on the person and the place! In my home in Shanghai, If we cook, it’ll be some Chinese, mostly Shanghainese dishes like 番茄炒蛋，红烧肉，油面筋塞肉，or other Chinese dishes. If we order deliveries, it’ll be foods from all over China and the world. For me, I usually order foods including Japanese Udon, ramen, Gyudon, Chinese ramen, Chinese stir fired rice, sometimes hamburgers, pizza and spaghetti!