The book 'I Like You A Little More Every Day' fit the description of the problem. The male lead was a tall and cold man, and the female lead was originally fat. Later, under the encouragement of the male lead, she became confident and beautiful. The male protagonist kept changing girlfriends due to external pressure, causing the female protagonist to be disheartened, but in the end, the two met again and achieved happiness. I hope you like my recommendation. Muah ~