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Introduction[edit]

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" or central obesity, and is more common in males than in females. Thus, the android fat distribution of man is about 48.6%, which is 10.3% higher than premenstrual women.[1] 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 with age as they carry more babies and approach the menopause. This distribution shifts towards the android pattern of fat distribution [2] and resulted in an increase to 42.1% of android body fat distribution in postmenstrual women. [1]


Android fat distribution is contrasted with gynoid fat distribution, fat around the hips, thighs and bottom, causing a "pear-shape". This more female-patterned fat distribution [3] has been linked to risk factors for cardiovascular disease in both males and females.[4] Jean Vague was one of the first individuals to bring to attention the increased risk of developing certain diseases in individuals with an android distribution compared to a gynoid distribution.

In other cases, an ovoid shape forms which does not differentiate between men and women.

Biology[edit]

The presence of fat in the trunk and upper body in males is facilitated by testosterone. Low levels of testosterone have been found to be correlated with greater levels of fatty deposits around the stomach area. High levels of testosterone are correlated with the opposite. Android fat develops as a back-up source of energy when the male body is experiencing an imbalance, whereas gynoid fat develops after puberty, in order to better prepare the body for supporting a potential infant. [5] 50% of the variance in abdominal fat mass observed in humans is due to genetic factors [6]

Health Consequences[edit]

Differences in body fat distribution were found to be associated with high blood pressure, high triglyceride and lower high-density lipoprotein (HDL) cholesterol levels and high fasting and post-oral glucose insulin levels [7]

The android or male pattern of fat distribution has been associated with a higher incidence of coronary artery disease as well as an increase in resistance to insulin in obese children and adolescents.[8] Studies have also related central abdominal obesity (indicated via increased waist-hip ratio) with increases in peripheral fasting insulin levels.[citation needed] It has also been associated with a change in pressor response in circulation. In response to stress in a subject with central obesity the cardiac output dependent pressor response is shifted toward a generalised rise in peripheral resistance with an associated decrease in cardiac output.

There are differences in android and gynoid fat distribution among individuals which relates to various health issues among individuals. Android body fat distribution is related to high cardiovascular disease and mortality rate. People with android obesity have higher hematocrit and red blood cell count and higher blood viscosity than people with gynoid obesity. Blood pressure is also higher in those with android obesity which leads to cardiovascular disease. [9]

Women who are Infertile and have polycystic ovary syndrome show high amounts of android fat tissue whereas patients with anorexia nervosa have increased gynoid fat percentage [10]

High levels of android fat have been associated with obesity [11] and diseases caused by insulin insensitivity, such as diabetes.[12].

Along with obesity, body fat distribution is related to offspring sex ratios. Peoples hormonal profiles are associated with android body fat distribution where Women with large waists tend to have more offsprings . [13]

Waist Hip Ratio[edit]

See Gynoid fat distribution

Central obesity is measured as increase in waist circumference or waist-hip ratio. Increase in waist circumference > 102 cm (40 in.) in males and > 88 cm (35 in.) in females. However increase in abdominal circumference may be due to increase in subcutaneous or visceral fat, and it is the visceral fat which increases risk of coronary diseases. The visceral fat can be estimated with the help of MRI and CT scan.

In females, measures of Waist to Hip ratio have been observed as an evolutionary sign of attractiveness and reproductive success[14]. Waist to hip ratio is determined by an individual's proportions of android fat and gynoid fat. A small waist to hip ratio indicates less android fat, high waist to hip ratio's indicate high levels of android fat.

Liposuction[edit]

Liposuction is a medical procedure used to removed fat from the body, common areas being around the abdomen, thighs and buttocks. Liposuction does not improve an individuals health or insulin sensitivity [15]. Therefore, Liposuction is considered a cosmetic surgery [16]. In evolutionary terms, liposuction can lower a person's waist-hip ratio by removing fat, giving the appearance of a more attractive body shape.

Individual Differences[edit]

Cultural Differences[edit]

Cultural differences in the distribution of android fat has been observed in several studies. Compared to Europeans, South Asian individuals living in the UK have greater abdominal fat. [17] Asian Indians living in the USA have high levels of body fat in contrast to their muscle mass and BMI [18] Newborn babies in India also show similar differences in their body fat distribution. [19] There is a difference in wait-to-hip ratio (WHR’s) between Indian people and Africans living in South Africa such that Indians have greater WHR’s compared to African people. [20] A difference in body fat distribution was observed between men and women living in Denmark (this includes both anroid fat distribution and gynoid fat distribution), of those aged between 35 to 65 years, men showed greater body fat mass than women. Men showed a total body fat mass of 6.9kg and women showed a total body fat mass of 4.5kg. [21] These observed difference could be due to a difference in muscularity [22]

References[edit]

  1. ^ a b Ley, Christopher J., Belinda Lees, and John C. Stevenson. (1992). "Sex-and menopause-associated changes in body-fat distribution". The American Journal of Clinical Nutrition. 55.5 (1992): 950-954. 55 (5): 950–4. doi:10.1093/ajcn/55.5.950. PMID 1570802.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  2. ^ Wells, Jonathan C.K (2007). "Sexual dimorphism of body composition". Best Practice & Research Clinical Endocrinology & Metabolism. 21 (3): 415–430. doi:10.1016/j.beem.2007.04.007. PMID 17875489.
  3. ^ Bray, George A. (2004-06-01). "Medical Consequences of Obesity". The Journal of Clinical Endocrinology & Metabolism. 89 (6): 2583–2589. doi:10.1210/jc.2004-0535. ISSN 0021-972X. PMID 15181027.
  4. ^ Wiklund, Peder; Toss, Fredrik; Weinehall, Lars; Hallmans, Göran; Franks, Paul W.; Nordström, Anna; Nordström, Peter (2008-11-01). "Abdominal and Gynoid Fat Mass Are Associated with Cardiovascular Risk Factors in Men and Women". The Journal of Clinical Endocrinology & Metabolism. 93 (11): 4360–4366. doi:10.1210/jc.2008-0804. ISSN 0021-972X. PMID 18728169.
  5. ^ Thornhill (2008). The Evolutionary Biology of Human Female Sexuality. ISBN 9780195340983.
  6. ^ Ali, A; Crowther, N (2005). "Body fat distribution and insulin resistance". SAMJ. 95 (11): 878–880. PMID 16344887.
  7. ^ Ali, Aus; Nigel, Crowther (2005). "Body fat distribution and insulin resistance". South African Medical Journal (95): 878–880. PMID 16344887.
  8. ^ Aucouturier J; Meyer M; Thivel D; Taillardat M; Duché P (2009-09-07). "EFfect of android to gynoid fat ratio on insulin resistance in obese youth". Archives of Pediatrics & Adolescent Medicine. 163 (9): 826–831. doi:10.1001/archpediatrics.2009.148. ISSN 1072-4710. PMID 19736336.
  9. ^ Wysocki, Marian; Krotkiewski, Marcin; Braide, Magnus; Bagge, Ulf (3 January 1991). "Hemorheological disturbances, metabolic parameters and blood pressure in different types of obesity". Atherosclerosis. 88 (1): 21–28. doi:10.1016/0021-9150(91)90253-y. PMID 1878007. Retrieved 2 March 2016.
  10. ^ Kirchengast, Sylvia; Huber, Johannes (2004). "Body composition characteristics and fat distribution patterns in young infertile women". Fertility and Sterility. 81 (3): 539–44. doi:10.1016/j.fertnstert.2003.08.018. PMID 15037399.
  11. ^ Lewis, G.; Carpentier, A.; Adeli, K.; Giacca, A. (2003). "Disorded fat storage and mobilization in the pathogenesis of unsulin resistance and type 2 diabetes". Endocrine Reviews. 23: 20-229.
  12. ^ Blouin, K; Boivin, A; Tchernof, A (2008). "Androgens and body fat distribution". The Journal of Steroid Biochemistry and Molecular Biiology. 108 (3): 272-280. doi:10.1016/j.jsbmb.2007.09.001. PMID 17945484. S2CID 11133007.
  13. ^ Abu-Rmeileh, Niveen; Watt, Graham; Lean, Michael (2011). "sex differences of offspring-parents obesity: Angely hypothesis revisited" (PDF). Human Biology. 83 (4): 523–530. doi:10.3378/027.083.0406. PMID 21846208. S2CID 2302428.
  14. ^ Singh, Devendra (1993). "Adaptive significance of female physical attractiveness: role of waist-to-hip ratio". Journal of Personality and Social Psychology. 65 (2): 293–307. doi:10.1037/0022-3514.65.2.293. PMID 8366421.
  15. ^ Wenk, Gary. "Your Brain on Food". Psychology Today. Retrieved 02/03/2016. {{cite web}}: Check date values in: |accessdate= (help)
  16. ^ Nordqvist, Christian. "What is liposuction? What are the risks and benefits of havings liposuction?". Medical News Today. Knowledge Center. Retrieved 02/03/2016. {{cite web}}: Check date values in: |accessdate= (help)
  17. ^ McKeigue, PM; Shah, B; Marmot, MG (1991). "Relation of central obesity and insulin resistance with high diabetes prevalence and cardiovascular risk in South Asians". Lancet 1991. 337 (8738): 382–386. doi:10.1016/0140-6736(91)91164-p. PMID 1671422. S2CID 21350831.
  18. ^ Banerji, MA; Faridi, N; Atluri, R; Chaiken, RL; Lebovitz, HE. "Body composition visceral fat, leptin and insulin resistance in Asian Indian Men". J Clin Endocrinol Metab 1999. 84: 137–144. PMID 9920074.
  19. ^ Bavdekar, A; Yajnik, CS; Fall, CHD; et al. "Insulin resistance syndrome in 8-year-old Indian children". Diabetes 1999. 48: 2422–2429. {{cite journal}}: Explicit use of et al. in: |last3= (help)
  20. ^ Naran, NH; Chetty, N; Toman, M; Crowther, NJ (2003). "Differences in insulin sensitivity and beta cell function in 3 South African ethnic groups. Journal of the Society for Endocrinology, Metabolism and Diabetes of South Africa". 8: 30.
  21. ^ Heitmann, BL (1991). "Body fat in the adult Danish population aged 35-65 years: an epidemiological study". International Journal of Obesity. 15 (8): 535–545. PMID 1938097.
  22. ^ Laulu, Manaia; Simmons, David; Rush, Elaine; Plank, Lindsay; Chandu, Vishnu (Dec 17, 2004). "Body size, body composition, and fat distribution: a comparison of young New Zealand men of European, Pacific Island, and Asian Indian ethnicities". The New Zealand Medical Journal (Online). 117 (1207): 117–1207. PMID 15608799.

Category:Obesity


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