Female body shape is the cumulative product of a woman's skeletal structure (her build) and the quantity and distribution of muscle and fat on the body. There are, and have been, wide differences on what should be considered an ideal or preferred body shape, both for attractiveness and for health reasons. These have varied among cultures and at different times. As with most physical traits, there is a wide range of normality of female body shapes. Human beings and their cultures have perennially focused attention on the female body as a source of aesthetic pleasure, sexual attraction, fertility, and reproductive appeal.
The female body occurs in a range of shapes. The female figure is typically narrower at the waist than at the bust and hips, and usually has one of four basic shapes: banana, pear, apple, or hourglass. The bust, waist, and hips are called inflection points, and the ratios of their circumferences define these basic shapes. Usually, the bust area will depend on the person's weight and height.
A woman's bust, waist and hips are her physical inflection points, and the ratios of their circumferences, are used to define her basic shape. These are sometimes described as banana, pear, apple or hourglass shapes.
The bust is measured across the fullest part of a woman's breasts, generally across the nipple line when wearing a properly-fitting brassiere (see: Brassiere measurements); the waist is measured at the smallest circumference of the abdomen; and the hips are measured at the largest circumference of the hips and buttocks.
The hourglass shape is the Western conception of the ideal or usual female shape, against which other shapes are compared. It is said that the female body usually inflects inward towards the waist around the middle of the abdomen between the costal margins and the pelvic crests. The waist is typically smaller than the bust and hips, unless there is a high proportion of body fat distributed around the waist. How much the bust or hips inflect inward, towards the waist determines the structural shape. In practice only about 8% of women have the hourglass shape.
Independent of fat percentage, weight or width, female body shapes are categorised into one of four elementary geometric shapes, though there are very wide ranges of actual sizes within each shape:
A study of over 6,000 women carried out by researchers at the North Carolina State University around 2005 found that 46% were banana (rectangular), just over 20% pear, just under 14% apple, and 8% hourglass. Another study has found "that the average woman's waistline had expanded by six inches since the 1950s" and that today women are taller and have bigger busts and hips than those of the 1950s.
A woman's "dimensions" are often expressed by the circumference around the three inflection points. For example, "36-29-38" in imperial units would mean a 36" bust, 29" waist and 38" hips. The measures are sometimes called a woman's vital statistics.
A woman's bust measure incorporates her breast size, as reflected in her bra cup size. For example, a woman with a bra size of 36A has a rib cage of 35-36 inches in circumference and a bust measure of 37 inches; a woman with a bra size 34C has a rib cage of 33-34 inches around, but the same bust measure of 37 inches. However, the woman with a 34C breast size will appear "bustier" and "hippier" because of the apparent difference in bust to hip ratios (narrower shoulders, more prominent breasts) even though they both have the same BWH ratio.
Height will also affect the appearance of the figure. A woman who is 36-24-36 at 5 ft 2 in (1.57 m) height will look different from a woman who is 36-24-36 at 5 ft 8 in (1.73 m) height. Since the taller woman's figure has greater distance between measuring points, she will likely appear thinner or less curvy than her shorter counterpart, again, even though they both have the same BWH ratio and the same weight. This is because the taller woman is actually thinner as expressed by her lower BMI, or body mass index, used to measure body fat in relation to height.
The use of BWH measurements for anything other than garment fitting is thus something of a shell game when applied to social body acceptance and evaluation. BWH is an indicator of fat distribution, not fat percentage.
The British Association of Model Agents (AMA) says that female models should be around 34-24-34 in (86-60-86 cm) and at least 5 ft 7 in (1.70 m) tall.
The aging process has an inevitable impact on a person's body shape. A woman's sex hormone levels will affect the fat distribution on her body. Concentrations of estrogen will influence where body fat is stored.
Before puberty both males and females have a similar waist-hip ratio. At puberty, a girl's sex hormones, mainly estrogen, will promote breast development, and until menopause a woman's estrogen levels will cause her body to store excess fat in the buttocks, hips and thighs, but generally not around her waist, which will remain about the same size as it was before puberty. These factors result in women's WHR being lower than for males. During and after pregnancy, a woman experiences body shape changes. After menopause, with the reduced production of estrogen by the ovaries, there is a tendency for fat to redistribute from a female's buttocks, hips and thighs to her waist or abdomen.
At times artificial devices are used or surgery is employed. Breast size can be artificially increased or decreased. Falsies, breast prostheses or padded bras may be used to increase the apparent size of a woman's breasts, while minimiser bras may be used to reduce the apparent size. Breasts can be surgically enlarged using breast implants or reduced by the systematic removal of parts of the breasts.
Historically, the greatest efforts have been made to reduce a woman's waist line. Boned corsets were used for several centuries, but during the twentieth century these were mostly replaced with more flexible foundation garments. Where corsets are used for waist reduction, it may be temporary reduction by occasional use or permanent reduction by people who are often referred to as tightlacers. Liposuction is the common surgical method of reducing the waist size.
Padded control briefs or hip and buttock padding may be used to increase the apparent size of hips and buttocks. Buttock augmentation surgery may be used to increase the size of hips and buttocks and to make them more rounded.
Each society develops a general perception of what an ideal female body shape would be like. These ideals are generally reflected in the art and literature produced by or for a society, as well as in popular media such as films and magazines. The ideal or preferred female body size and shape has varied over time and continues to vary among cultures; but a preference for a small waist has remained fairly constant throughout history. A low waist-hip ratio has often been seen as a sign of good health and reproductive potential.
A low waist-hip ratio has also often been regarded as an indicator of attractiveness of a woman, but recent research suggests that attractiveness is more correlated to body mass index than waist-hip ratio, contrary to previous belief. Historically, according to Devendra Singh, there was a trend for slightly larger women in the 17th and 18th centuries, as typified by the paintings of Rubens, but that in general there has been a preference for a slimmer waist in Western culture. She notes that "The finding that the writers describe a small waist as beautiful suggests instead that this body part - a known marker of health and fertility - is a core feature of feminine beauty that transcends ethnic differences and cultures."
New research suggests that apple-shaped women have the highest risk of developing heart disease, while hourglass-shaped women have the lowest. Diabetes professionals advise that a waist measurement for a woman of over 80cm increases the risk of heart disease, but that ethnic background also plays a factor. This is because body fat buildup around the waist (the apple shape) poses a higher health risk than a fat buildup at the hips (the pear shape).
The waist-hip ratio (WHR) is a person's waist measurement divided by the hip measurement. Notwithstanding wide cultural differences in preferences for female build, scientists have discovered that the waist-hip ratio of any build is very strongly correlated to the perception of attractiveness across all cultures. Women with a 0.7 WHR (waist circumference that is 70% of the hip circumference) are usually rated as more attractive by men from European cultures. Such diverse beauty icons as Marilyn Monroe, Sophia Loren, and the Venus de Milo all have ratios around 0.7. In other cultures, preferences vary, ranging from 0.6 in China, to 0.8 or 0.9 in parts of South America and Africa, and divergent preferences based on ethnicity, rather than nationality, have also been noted.
Body image refers to the perceptions of a human's own physical appearance, or the internal sense of having a body which is interpreted by the brain. Essentially a person's body image is how they perceive their exterior to look, and in many cases this can be dramatically different from how they actually appear to others. Studies have found that females tend to think more about their body shape and endorse thinner figures than men even into old age. When female undergraduates were exposed to depictions of thin women their body satisfaction decreased, but rose when exposed to larger models.
Many commentators regard the emphasis in the media and in the fashion industry on thinness and on an ideal female body size and shape as being psychologically detrimental to the well-being of many young women, and on their self-image which also gives rise to excessive dieting and/or exercise, and to eating disorders such as anorexia nervosa. Sociocultural studies highlight the role of cultural factors in the incidence of anorexia nervosa in women, such as the promotion of thinness as the ideal female form in Western industrialized nations, particularly through the media. A recent epidemiological study of 989,871 Swedish residents indicated that gender, ethnicity and socio-economic status were highly correlated with the chance of developing anorexia nervosa, and women with non-European parents were among the least likely to be diagnosed, while women in wealthy, ethnic Swedish families were most at risk.
A study by Garner and Garfinkel demonstrated that those in professions where there is a particular social pressure to be thin (such as models and dancers) were much more likely to develop anorexia during their career, and further research suggests that those with anorexia have much higher contact with cultural sources that promote weight-loss.
Although anorexia nervosa is usually associated with Western cultures, exposure to Western media is thought to have led to an increase in cases in non-Western countries. But other cultures may not display the same worries about becoming fat as those in the West, and instead may emphasise other common features.