Gynoid fat is the body fat that forms around the hips, breasts, and thighs. [1] Gynoid fat in females is used to provide nourishment for offspring, and is often referred to as 'reproductive fat'. This is because it contains long-chain polyunsaturated fatty acids (PUFAs), which are important in the development of fetuses. [2] It is regarded as a physically attractive feature, serving as an indication towards a woman's reproductive potential. [3]
Gynoid fat is mainly composed of long-chain polyunsaturated fatty acids. [2] It is proposed that babies which are breast-fed are more likely to have increased cognitive capabilities due to these fatty acids being present in the breast milk, as they have been suggested to aid early brain development in fetuses and newborns. [4] The most notable fatty acids found in human breast milk are docosahexaenoic acid and arachidonic acid, which have been shown to play crucial roles in the healthy formation and functions of neurons. [5]
Gynoid fat contributes toward the female body shape that girls begin to develop at puberty; it is stored in the breasts and the hips, thighs and bottom. [6] This process is modulated by estrogen, the female sex hormone, causing the female form to store higher levels of fat than the male form, which is affected primarily by testosterone. [7]
The location of android fat differs in that it assembles around internal fat depots and the trunk (includes thorax and abdomen). [2] Android fat has more of a survival role and is utilised by the body as an energy source when energy supplies are low, in contrast to the reproductive functions of gynoid fat. [8]
Gynoid fat is primarily a store of energy to be expended in the nurturing of offspring, both to provide adequate energy resources during pregnancy and for the infant during the stage in which they are breastfeeding. [9] When there are insufficient energy resources in the environment or health issues which require energy to combat, a woman's storage of gynoid fat is likely to be reduced. Therefore, a female with high levels of gynoid fat would be signalling to males that they are in an optimal state for reproduction and nurturing of offspring. This can be seen in the fact that a female's waist–hip ratio is at its optimal minimum during times of peak fertility—late adolescence and early adulthood, before increasing later in life. [10]
As a female's capacity for reproduction comes to an end, the fat distribution within the female body begins a transition from the gynoid type to more of an android type distribution. This is evidenced by the percentages of android fat being far higher in post-menopausal than pre-menopausal women. [11] [12]
The differences in gynoid fat between men and women can be seen in the typical "hourglass" figure of a woman, compared to the inverted triangle which is typical of the male figure. Women commonly have a higher body fat percentage than men and the deposition of fat in particular areas is thought to be controlled by sex hormones and growth hormone (GH). [13]
The hormone estrogen inhibits fat placement in the abdominal region of the body, and stimulates fat placement in the gluteofemoral areas (the buttocks and hips). Certain hormonal imbalances can affect the fat distributions of both men and women. Women suffering from polycystic ovary syndrome, characterised by low estrogen, display more male type fat distributions such as a higher waist-to-hip ratio. Conversely, men who are treated with estrogen to offset testosterone related diseases such as prostate cancer may find a reduction in their waist-to-hip ratio. [14]
Sexual dimorphism in distribution of gynoid fat was thought to emerge around puberty but has now been found to exist earlier than this. [15]
Gynoid fat bodily distribution is measured as the waist-to-hip ratio (WHR), whereby if a woman has a lower waist-to-hip ratio it is seen as more favourable. [17] Studies have found correlations between WHR and intelligence quotient (IQ) levels. It was found not only that women with a lower WHR (which signals higher levels of gynoid fat) had higher levels of IQ, but also that low WHR in mothers was correlated with higher IQ levels in their children. [18]
Android fat distribution is also related to WHR, but is the opposite to gynoid fat. The ratio of a woman’s gynoid to android fat is used to measure her WHR, whereby the lower the WHR, the higher gynoid to android fat ratio. Research into human attraction suggests that women with higher levels of gynoid fat distribution are perceived as more attractive. [19] WHR is related to various markers of health and fertility, for example a high WHR is correlated with: a low estrogen/testosterone ratio (this means that a woman has more of a 'T-shaped' body which is seen as less healthy and attractive); a high ratio is also correlated to circulatory system problems such as heart attacks and strokes; more disease (e.g. cancer); and is a general sign of increased age and hence lower fertility, therefore supporting the adaptive significance of an attractive WHR. [20] This advantage of being more fertile has been supported by various studies, for example artificial insemination studies involving sperm donors, where the best predictor of success is a low WHR. [21] Similarly, a high WHR has been associated with impairment in the pregnancy rate of IVF (in vitro fertilisation) embryo transfer women due to the higher levels of android fat distribution. [22] Further studies have also found that oestrogen replacement in women lowers the WHR in pre- and post-menopausal women, and that this is because oestrogen replacement maintains gynoid fat distribution in the body. [23]
Both android and gynoid fat are found in female breast tissue. [24] Females develop breasts around puberty and breasts with less android fat and more gynoid fat are firmer. Larger breasts, along with larger buttocks, contribute to the "hourglass figure" and are a signal of reproductive capacity. [25] The proportion of gynoid fat is a good predictor of female reproductive capability, such as conception probability and likelihood of successful pregnancy. [26] As humans evolved and became bipedal, other ways of signalling such as sexual swelling became less visible and consequently other forms of sexual signalling had to develop. [27] Being able to store an optimum amount of gynoid fat requires a female to have access to resources such as food and therefore is an honest signal of having sufficient energy resources to successfully reproduce. [27]
However, not all women have their desired distribution of gynoid fat, hence there are now trends of cosmetic surgery, such as liposuction or breast enhancement procedures which give the illusion of attractive gynoid fat distribution, and can create a lower waist-to-hip ratio or larger breasts than occur naturally. [28] Other examples include micrograft surgery, [29] which involves the deposition of adipose tissue, previously taken from the waist, into the buttocks. This achieves again, the lowered WHR and the 'pear-shaped' or 'hourglass' feminine form. [30]
There has not been sufficient evidence to suggest there are significant differences in the perception of attractiveness across cultures. Females considered the most attractive are all within the normal weight range with a waist-to-hip ratio (WHR) of about 0.7, regardless of body mass index (BMI), and this finding can be seen as consistent across Indonesian, Chinese, White and African-American young men and women. [29] [31] Psychologists have argued that evolutionary selection processes have facilitated this relationship between WHR and female attractiveness, which has resulted in a consensus that seems to transcend cultural boundaries. [32]
Gynoid fat is not associated with as severe health effects as android fat. Gynoid fat is a lower risk factor for cardiovascular disease than android fat. [33] However, excess body fat is the main source of estrogen in the body and therefore particularly high levels of gynoid fat can increase the risk of breast cancer developing. [34]
The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues.
Estrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal activity: estrone (E1), estradiol (E2), and estriol (E3). Estradiol, an estrane, is the most potent and prevalent. Another estrogen called estetrol (E4) is produced only during pregnancy.
A secondary sex characteristic is a physical characteristic of an organism that is related to or derived from its sex, but not directly part of its reproductive system. In humans, these characteristics typically start to appear during puberty. In animals, they can start to appear at sexual maturity. In humans, secondary sex characteristics include enlarged breasts and widened hips of females, facial hair and Adam's apples on males, and pubic hair on both. In non-human animals, secondary sex characteristics include, for example, the manes of male lions, the bright facial and rump coloration of male mandrills, and horns in many goats and antelopes.
Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of female reproductive cycles such as estrous and menstrual cycles. Estradiol is responsible for the development of female secondary sexual characteristics such as the breasts, widening of the hips and a female-associated pattern of fat distribution. It is also important in the development and maintenance of female reproductive tissues such as the mammary glands, uterus and vagina during puberty, adulthood and pregnancy. It also has important effects in many other tissues including bone, fat, skin, liver, and the brain.
Body proportions is the study of artistic anatomy, which attempts to explore the relation of the elements of the human body to each other and to the whole. These ratios are used in depictions of the human figure and may become part of an artistic canon of body proportion within a culture. Academic art of the nineteenth century demanded close adherence to these reference metrics and some artists in the early twentieth century rejected those constraints and consciously mutated them.
Physical attractiveness is the degree to which a person's physical features are considered aesthetically pleasing or beautiful. The term often implies sexual attractiveness or desirability, but can also be distinct from either. There are many factors which influence one person's attraction to another, with physical aspects being one of them. Physical attraction itself includes universal perceptions common to all human cultures such as facial symmetry, sociocultural dependent attributes and personal preferences unique to a particular individual.
Raloxifene, sold under the brand name Evista among others, is a medication used to prevent and treat osteoporosis in postmenopausal women and those on glucocorticoids. For osteoporosis it is less preferred than bisphosphonates. It is also used to reduce the risk of breast cancer in those at high risk. It is taken by mouth.
The waist–hip ratio or waist-to-hip ratio (WHR) is the dimensionless ratio of the circumference of the waist to that of the hips. This is calculated as waist measurement divided by hip measurement. For example, a person with a 75 cm waist and 95 cm hips has WHR of about 0.79.
Human male sexuality encompasses a wide variety of feelings and behaviors. Men's feelings of attraction may be caused by various physical and social traits of their potential partner. Men's sexual behavior can be affected by many factors, including evolved predispositions, individual personality, upbringing, and culture. While most men are heterosexual, there are minorities of homosexual or varying degrees of bisexual men.
The hourglass figure is one of four traditional female body shapes described by the fashion industry. The other shapes are the rectangular, inverted triangle, and spoon/pear. The hourglass shape is defined by a woman's body measurements- the circumference of the bust, waist and hips. Hourglass body shapes have a wide bust, a narrow waist, and wide hips with a similar measurement to that of the bust. This body shape is named for its resemblance to that of an hourglass where the upper and lower half are wide and roughly equal while the middle is narrow in circumference, making the overall shape wide-narrow-wide. Women who exhibit the hourglass figure have been shown to be more admired, which can put pressure on women whose body shapes are noticeably different to strive to achieve the hourglass figure. This can lead to body dissatisfaction which can cause eating disorders in young women from all over the globe.
Human body shape is a complex phenomenon with sophisticated detail and function. The general shape or figure of a person is defined mainly by the molding of skeletal structures, as well as the distribution of muscles and fat. Skeletal structure grows and changes only up to the point at which a human reaches adulthood and remains essentially the same for the rest of their life. Growth is usually completed between the ages of 13 and 18, at which time the epiphyseal plates of long bones close, allowing no further growth.
Sexual selection in humans concerns the concept of sexual selection, introduced by Charles Darwin as an element of his theory of natural selection, as it affects humans. Sexual selection is a biological way one sex chooses a mate for the best reproductive success. Most compete with others of the same sex for the best mate to contribute their genome for future generations. This has shaped human evolution for many years, but reasons why humans choose their mates are not fully understood. Sexual selection is quite different in non-human animals than humans as they feel more of the evolutionary pressures to reproduce and can easily reject a mate. The role of sexual selection in human evolution has not been firmly established although neoteny has been cited as being caused by human sexual selection. It has been suggested that sexual selection played a part in the evolution of the anatomically modern human brain, i.e. the structures responsible for social intelligence underwent positive selection as a sexual ornamentation to be used in courtship rather than for survival itself, and that it has developed in ways outlined by Ronald Fisher in the Fisherian runaway model. Fisher also stated that the development of sexual selection was "more favourable" in humans.
Hormone replacement therapy (HRT), also known as menopausal hormone therapy or postmenopausal hormone therapy, is a form of hormone therapy used to treat symptoms associated with female menopause. Effects of menopause can include symptoms such as hot flashes, accelerated skin aging, vaginal dryness, decreased muscle mass, and complications such as osteoporosis, sexual dysfunction, and vaginal atrophy. They are mostly caused by low levels of female sex hormones that occur during menopause.
Estrogenic fat is a form of adipose tissue which develops under the influence of estrogen, and particularly estradiol, in women.
Female body shape or female figure is the cumulative product of a woman's bone structure along with the distribution of muscle and fat on the body.
Android fat distribution describes the distribution of human adipose tissue mainly around the trunk and upper body, in areas such as the abdomen, chest, shoulder and nape of the neck. This pattern may lead to an "apple”-shaped body or central obesity, and is more common in males than in females. Thus, the android fat distribution of men is about 48.6%, which is 10.3% higher than that of premenopausal women. In other cases, an ovoid shape forms, which does not differentiate between men and women. Generally, during early adulthood, females tend to have a more peripheral fat distribution such that their fat is evenly distributed over their body. However, it has been found that as females age, bear children and approach menopause, this distribution shifts towards the android pattern of fat distribution, resulting in a 42.1% increase in android body fat distribution in postmenopausal women. This could potentially provide evolutionary advantages such as lowering a woman's center of gravity making her more stable when carrying offspring.
Devendra Singh was a professor of Psychology at the University of Texas, known largely for his research regarding the evolutionary significance of human attraction.
Mate preferences in humans refers to why one human chooses or chooses not to mate with another human and their reasoning why. Men and women have been observed having different criteria as what makes a good or ideal mate. A potential mate's socioeconomic status has also been seen important, especially in developing areas where social status is more emphasized.
Mate value is derived from Charles Darwin's theory of evolution and sexual selection, as well as the social exchange theory of relationships. Mate value is defined as the sum of traits that are perceived as desirable, representing genetic quality and/or fitness (biology), an indication of a potential mate's reproductive success. Based on mate desirability and mate preference, mate value underpins mate selection and the formation of romantic relationships.
Female intrasexual competition is competition between women over a potential mate. Such competition might include self-promotion, derogation of other women, and direct and indirect aggression toward other women. Factors that influence female intrasexual competition include the genetic quality of available mates, hormone levels, and interpersonal dynamics.
