Why did the Tang Dynasty regard plump women as beautiful women?

Empress Wu Zetian and imperial concubine Yang Yuhuan, who stood out in the real life of the Tang Dynasty, can be regarded as the model of "being rich, rich and beautiful, and posing warmly". Wu Zetian, the only female emperor in the history of China, stepped into the peak of power with her beauty, wisdom and courage. Although there was no camera or painting to record her true face at that time, we can conclude from the description of "square forehead, broad eyes and phoenix neck" in the history books that she won the status of "obsequious mother" with her broad forehead, plump cheeks, round and overlapping neck and rich image, thus laying the foundation for her to get closer to the power center. Yang Yuhuan, one of the four great beauties in ancient China, is a well-known and eternal model of fat beauty. However, we have the same regret as Empress Wu Zetian. We can only imagine her beauty of "if she but turned her head and smiled, there were cast a hundred spells, and the powder and paint of the Six Palaces faded into nothing" according to the description in records and poems, and infer her charming demeanor from the historical facts of "and the Emperor, from that time forth, forsook his early hearings". "Surrounding fat and being thin" summarized the different aesthetic standards of Han and Tang dynasties, and also fixed the beautiful shape of Yang Yuhuan's "rich and beautiful". Obviously, both works of art and real life clearly reflect that the Tang people really advocate "fat and beautiful, warm and graceful." This is different from the implicit and introverted aesthetic appreciation of my fair lady in Han Dynasty and most ancient times, and formed an "alternative" aesthetic vision in Tang Dynasty. However, this kind of "otherness" and the charm contrary to the traditional plump beauty are not only not inferior to the traditional slimness and sense of bone, but also more vital and energetic. In fact, after a little analysis, we will find that the "alternative" aesthetics of the Tang people is the inevitable feature of that heyday. First of all, the Tang Dynasty was prosperous, well-fed and well-fed, as the poet Du Fu wrote, "The rice is fat and the millet is white, and the public and private warehouses are rich." People have the conditions to eat and wear warm clothes to keep healthy and plump physique. Secondly, the Tang Dynasty was open and inclusive. Strong national strength and developed civilization have made the Tang people confident and become a highly open country. According to incomplete statistics, there were more than 13 countries associated with Tang at that time. Influenced and blended by different cultures, people in the Tang Dynasty are not limited to tradition, and their horizons are broadened and they are enthusiastic. Third, the lineage of the rulers also determines that the Tang people are more close to their strong bodies. The grandfather of Tang Dynasty's founding emperor, Li Yuan, was big noble Dugu, who wished to be born in Xianbei. That is to say, at least half of Li Tang's royal blood was Xianbei, and the nomadic life of Xianbei people created and needed a wild and strong body. Therefore, it is not difficult to understand that several generations of monarchs in the Tang Dynasty loved fat women.