The main reason why the photos taken are fatter and shorter than the real people is that the people seen in reality are three-dimensional, while the real people in the photos are two-dimensional, and the two-dimensional images displayed in people's brains are wider and bigger than the three-dimensional images, that is, people are fat and short.
The way to solve the problem of being fatter and shorter than a real person in a photo: make the photographer's facial features and figure more stereoscopic through the change of light and shade, especially when taking portraits, people's clothes are dark black, which will make people thinner and taller. Pay more attention to the change of light and the color matching between people and environment when taking pictures, which can restore the real reality well.
When taking pictures, if you want to make people thinner, you can also consider taking pictures with a wide-angle lens. Reasonable use of wide-angle lens distortion can better shape people's figure.
Finally, you can adjust the lightness and thinness slightly through the liquefaction function of PS digital later stage to better modify the photos.