Healthy premenopausal women have waist-to-hip ratios of .67 to .80. This means that their waist circumferences are seven to eight tenths as large as their hips. A healthy man's waist-to-hip ratio is between 0.85 and 0.95. Moderate weight gain does not alter these basic male and female shapes, and they are found all over the world among people who vary considerably in height and weight.

Men have an innate preference for female bodies with narrow waists and full hips, which signal high fertility, high estrogen, and low testosterone. Cartoon characters and virtual images of females like Jessica Rabbit (Who Framed Roger Rabbit, 1988) and Lara Croft typically have exaggerated proportions. Barbie has measurements of 36-18-33, with a 0.54 waist-to-hip ratio. Audrey Hepburn and Marilyn Monroe represented two different images of in the 1950s. Yet, the 36-24-34 Marilyn and the 31.5-22-31 Audrey both had versions of the hourglass shape and waist-to-hip ratios of .70. During the 20th century, Miss Americas' and Playboy centerfolds' waist-to-hip ratios measurements ranged from 0.68 to 0.72. By the end of the 20th century, the average supermodel measured 33-23-33, giving her a 0.7 waist-to-hip ratio.

The Miss Americas of the 1960s were five feet six inches tall and weighed 120 pounds. Twenty years later they had gained two inches in height but remained the same weight. Playboy playmates also dropped several pounds and gained several inches in height during the same period, dipping from 11% below the national average to 17% below it. Even the Columbia Pictures logo, the torch-bearing woman, was slimmed in 1992.

Presently, 64% of American Adults are overweight, defined as having a body mass index of 25 or greater, and 31% are obese, having a body mass of 30 or greater