Female body shape

Female body shape has a bearing on a wide range of human activities, and there are and have been widely different ideals of it in different cultures over history. The female figure is usually narrower at the waist than at the chest and hips, and usually has one of four basic shapes — banana, pear, apple or hourglass. The chest, waist and hips are called inflection points, and the ratios of their circumferences define these basic shapes. Body shape depends on skeletal structure and the distribution of fat and muscle in the body.

Some of these body shapes normally occur only in genetic women, although some endocrine conditions or deliberate use of female hormones, such as by transsexuals, can produce them in previously male bodies. As with most physical traits, there is a wide range of normal female body shapes.

Shape

The female form is a combination of multiple attributes which cause many conflicting descriptions when taken as a whole.

Three extremal points

The female body has three key physical inflection points:

* Chest, which is measured across the fullest part of the bust
* Waist, which is usually measured at the smallest circumference of the abdomen
* Hips, which is usually measured at the largest circumference of the hips and buttocks

The female body usually inflects inward towards the waist around the middle of the abdomen. The waist is smaller than the chest and hips, unless there is a high proportion of body fat distributed around the waist. How much the chest or hips inflect inward, towards the waist determines the structural shape.

A woman's "dimensions" are often presented by the circumference around these three inflection points. For example "36-29-38" in Imperial units, meaning a 36" chest, 29" waist and 38" hips.

Four combinatorial structures

Independent of fat percentage, weight or width, most female bodies have one of four elementary geometries, ordered by their commonality in western societyHow female body shapes have changed over time http://news.independent.co.uk/uk/this_britain/article328328.ece] .

; Banana or Straight: the waist circumference is at least 75% of the chest or hips circumferences, which are virtually the same. The body has a relatively high androgen level compared to the estrogen level, and this causes the skeleton to develop in a more masculine pattern and body fat to be distributed predominantly around the waist.

; Pear or Spoon or Bell (Triangle upward): the waist circumference is at least 75%dubious|date=September 2007 of the chest circumference, and the hips circumference is at least 110%dubious|date=September 2007 of the chest circumference. The distribution of fat varies, with fat tending to deposit first in the buttocks, hips and thighs. As body fat percentage increases, an increasing proportion of body fat is distributed around the waist and upper abdomen.

; Apple (Triangle downward): the waist circumference is at most 75% of the chest circumference, and the chest circumference is at least 110% of the hips circumference. Body fat distribution tends to begin in the arms, shoulders, chest and upper abdomen first.

; Hourglass shape (Triangles opposing, facing in): the waist circumference is less than 75% of the chest or hips circumferences, which are virtually the same. Body fat distribution tends to be around both the upper body and lower body. This body type enlarges the arms, breasts, hips and rear before other parts, including waist and upper abdomen. Due to the preference shown to physical symmetry, many celebrities falsely claim hourglass measurements but actually rate closer to a straight figure or apple.

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.

New research suggests that hourglass women may live longest, and apple-shaped the shortest [http://news.bbc.co.uk/2/hi/health/4606011.stm Curvier women 'will live longer'] .

The inflection points on the female form define a woman's combinational structure. Any structure can occur in a range of proportions.

Weight and fat distribution

Shape is affected by fat distribution due to sex hormone levels [ "body shape is determined by the nature of body fat distribution that, in turn, is significantly correlated with women's sex hormone profile, risk for disease, and reproductive capability" http://www.psichi.org/pubs/articles/article_548.asp] . The concentrations of estrogen influence where body fat is stored. Before puberty both males and females have similar WHR. [ [http://www.psichi.org/pubs/articles/article_548.asp An Evolutionary Theory of Female Physical Attractiveness - Psi Chi ] ] Normal pre-menopausal female estrogen levels will cause the body to store fat in the buttocks, thighs, and hips. [ estrogen causes fat to be stored around the pelvic region, hips, butt and thighs http://www.annecollins.com/obesity/reduce-abdominal-fat.htm] [ [http://www.healthywomen.org/columns/drpeekescolumn/dbcolumn/waistlineworriesturningapplesbackintopears Waistline Worries: Turning Apples Back Into Pears ] ] Hence, pre-menopausal females generally have fat distributed around their hip section but not around their waist. This causes their waist-hip ratio (waist measurement divided by hip measurement) to be lower than males. When women pass menopause, the estrogen produced by ovaries reduces, causing fat to redistribute from their buttocks, hips and thighs to their waist. [ "Researchers think that the lack of estrogen at menopause play a role in driving our fat northward" [http://health.yahoo.com/topic/nutrition/overview/article/womens-health/26287] ] Fat stored during subsequent weight gain is primarily concentrated in the abdomen.

Body Mass Index, which considers only height and total mass, is an approximate method for calculating whether an adult is overweight, underweight, or of a healthy weight. Some recent research indicates that the waist-hip ratio is a better measure of obesity than body mass index, particularly for the purpose of determining risk of heart attack. [ [http://www.medicalnewstoday.com/medicalnews.php?newsid=49218 American Journal of Clinical Nutrition August 12,2006] ] The ideal ratio for women is about 0.7Cite journal | title = Female Mate Value at a Glance: Relationship of Waist-to-Hip Ratio to Health, Fecundity, and Attractiveness | author = Singh, D. | year = 2002 | journal = Neuroendocrinology Letters |issue= Special Issue |volume= 23 |pages= p. 81–91] . The body fat percentage is considered to be an even more accurate measure of obesity. Of these three measurements, only the waist-hip ratio uses dimensions that will vary depending upon the body structure. Hence, it is possible for two women to have vastly different body mass indices but the same waist-hip ratio, or to have the same body mass index but vastly different waist-hip ratios.

The ideal female body size and shape varies among cultures [ [http://www.physorg.com/news112367616.html Ideal weight varies across cultures, but body image dissatisfaction pervades ] ] ; however, the preference for a small waist has remained fairly constant throughout history [ [http://news.bbc.co.uk/1/hi/health/6247625.stm BBC NEWS | Health | Slim waist holds sway in history ] ] . A low waist-hip ratio has often been seen as a sign of good reproductive potential, but recent research suggests that attractiveness is more correlated to body mass index than waist-hip ratio, contrary to previous belief [Tovee MJ, Maisey DS, Emery JL, Cornelissen PL. Visual cues to female physical attractiveness. "Proc Biol Sci." 1999 January 22;266(1415):211-8. PMID: 10097394 [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10097394&query_hl=2&itool=pubmed_docsum] ] [ [http://www.informaworld.com/smpp/content~content=a741405962~db=all~jumptype=rss The relative contributions of waist-to-hip ratio and body mass index to judgements of attractiveness - Sexualities, Evolution & Gender ] ] .

Societal impact

Many societies vary on their contrasts, criticisms and praise of the female form. Crowd leaders, such as celebrities, also impact the "desirable" female body shape [ [http://www.bignews.biz/?id=2141&keys=rockstar-anorexia-girls-support Australian Idol Starlet: Shocking Anorexic Revelations ] ] .

Social conditioning to obesity

As average body mass continues to increase in Western nations, people are becoming desensitized to obesity and view an increasingly larger amount of body fat as "normal" or "acceptable" [ [http://www.msnbc.msn.com/id/20895509/ Is fat the new normal? - Nutrition Notes - MSNBC.com ] ] . People are especially likely to take cues on acceptable body size from their social circle, gaining weight concurrently with those around them [ [http://content.nejm.org/cgi/content/full/357/4/370 NEJM - The Spread of Obesity in a Large Social Network over 32 Years ] ] .

Many "curvy" American film stars from the early and mid-20th century are cited as inspirations by overweight women when, in reality, they were thin even by today's standards. Marilyn Monroe is said to have worn a size 16 dress. However, this fails to consider the changes in American garment sizing over the last century. Monroe was 5'5", weighed 118 lbs and measured 36-24-34 [ [http://www.playboy.com/girls/playmates/directory/195312.html Playboy Data Sheet: Marilyn Monroe] ] , which would make her approximately a women's size 2 by modern American sizing standards.

Feminism and body shape

Feminists criticise the excessive emphasis on body shape as part of women's self-image in Western society, and contend that an ample body shape is more typical of real women in the West than the ideal pushed by some parts of the Western media through depictions of extremely thin actresses and fashion models. Fact|date=June 2008 However, in media made predominantly by and for heterosexual men, such as video games, comic books, sports entertainment, or pornography, a more buxom and curvaceous female ideal with large breasts, small waist and rounded hips is portrayed, one that is more in line with the sexual desires of men than those seen in the fashion or beauty industries.Fact|date=June 2008

Anorexia and media depictions of women

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 industrialised 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, 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. [Lindberg L, Hjern A. (2003) Risk factors for anorexia nervosa: a national cohort study. "Int J Eat Disord", 34 (4), 397-408. PMID 14566927]

A classic 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, [Garner DM, Garfinkel PE. (1980) Socio-cultural factors in the development of anorexia nervosa. "Psychol Med", 10 (4), 647-56. PMID 7208724.] and further research suggests that those with anorexia have much higher contact with cultural sources that promote weight-loss. [Toro J, Salamero M, Martinez E. (1994) Assessment of sociocultural influences on the aesthetic body shape model in anorexia nervosa. "Acta Psychiatrica Scandinavica", 89 (3), 147-51. PMID 8178671.]

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 with the condition in the West, but instead may present with low appetite with the other common features. [Simpson KJ. (2002) Anorexia nervosa and culture. "J Psychiatr Ment Health Nurs", 9 (1), 65-71. PMID 11896858.]

See also

* Body fat percentage
* Body mass index
* Glossary of shapes with metaphorical names
* Human variability
* Human body shape
* Physical attractiveness
* Sexual attraction
* Sexual dimorphism
* Waist-hip ratio
* Golden Ratio
* Bra Size
* Woman

References