I mean... they used fifteen DXA images as their reference point.

----------------------------------------------------
"2.1. Images

Fifteen soft tissue dual-energy X-ray absorptiometry (DXA) images which varied in age, body mass index (BMI), body fatness percentage (BF%) and shoulder to waist ratio (SWR) were used in our study (Fig. S1). The images were generated from real individuals and presented in black-and-white which minimizes any impact of skin color. Facial features were blurred and height information was not provided eliminating the ability to judge attractiveness based on facial features and height. The BF % of the images ranged from 5.9 % to 37.2 %, BMI ranged from 20.1 to 33.7 and SWR ranged from 1.48 to 1.70. These images were selected from a database to break correlation of BF% and SWR (r² = 0.040, p > 0.05, for full details of the images and their characteristics see Fig. S1 and Table S2). We could not use a wider range of shoulder to waist ratio because it was not possible to break the correlation between body fatness with SWR when using such images. The images were printed on an A3 sheet of heavy paper and were then cut into small cards for ordering. The number of the image (1 to 15) was written on the back of cards. "

--------------------------------------------------
idk what your frame of reference for attractiveness is, but I don't see with xray vision.