Diet and obesity

Map of dietary energy availability per person per day in 1961 (kcal/person/day).   no data   <1600   1600-1800   1800-2000   2000-2200   2200-2400   2400-2600   2600-2800   2800-3000   3000-3200   3200-3400   3400-3600   >3600

Map of dietary energy availability per person per day in 1979-1981 (kcal/person/day).[1]   no data   <1600   1600-1800   1800-2000   2000-2200   2200-2400   2400-2600   2600-2800   2800-3000   3000-3200   3200-3400   3400-3600   >3600

Map of dietary energy availability per person per day in 2001–2003 (kcal/person/day).[1]   no data   <1600   1600–1800   1800–2000   2000–2200   2200–2400   2400–2600   2600–2800   2800–3000   3000–3200   3200–3400   3400–3600   >3600

Diet plays an important role in the genesis of obesity. Personal choices, advertising, social customs and cultural influences, as well as food availability and pricing all play a role in determining what and how much an individual eats.

Dietary energy supply

Average per capita energy consumption of the world from 1961 to 2002

The dietary energy supply is the food available for human consumption, usually expressed in kilocalories per person per day. It gives an overestimate of the total amount of food consumed as it reflects both food consumed and food wasted.^[2] The per capita dietary energy supply varies markedly between different regions and countries. It has also changed significantly over time.^[3] From the early 1970s to the late 1990s, the average calories available per person per day (the amount of food bought) has increased in all part of the world except Eastern Europe and parts of Africa. The United States had the highest availability with 3654 calories per person in 1996.^[4] This increased further in 2002 to 3770.^[5] During the late 1990s, Europeans had 3394 calories per person, in the developing areas of Asia there were 2648 calories per person, and in sub-Sahara Africa people had 2176 calories per person.^[4][6]

Average calorie consumption

Change over time of the macronutrient composition of the US male diet.

Change over time of the macronutrient composition of the US female diet.

USDA chart showing the increase in soda consumption and the decrease in milk consumption from 1947 to 2001.^[7]

From 1971 – 2000, the average daily number of calories which women consumed in the United States increased by 335 calories per day (1542 calories in 1971 and 1877 calories in 2000). For men, the average increase was 168 calories per day (2450 calories in 1971 and 2618 calories in 2000). Most of these extra calories came from an increase in carbohydrate consumption rather than an increase in fat consumption.^[8] The primary sources of these extra carbohydrates were sweetened beverages, which now accounts for almost 25 percent of daily calories in young adults in America.^[9] As these estimates are based on a person's recall, they may underestimate the amount of calories actually consumed.^[8]

Fast food

As societies become increasingly reliant on energy-dense fast-food meals, the association between fast food consumption and obesity becomes more concerning.^[10] In the United States consumption of fast food meal has tripled and calorie intake from fast food has quadrupled between 1977 and 1995.^[11] Consumption of sweetened drinks is also believed to be a major contributor to the rising rates of obesity.^[12][13]

Portion size

A comparison of a typical cheeseburger 20 years ago (left) which had 333 calories with a modern cheeseburger (right) which contains 590 calories as per the National Heart, Lung, and Blood Institute

The portion size of many prepackage and restaurant foods have increased in both the United States and Denmark since the 1970s.^[8] Fast food serving for example 2 to 5 times larger than they were in the 1980s. Evidence has shown that larger portions of energy-dense foods lead to greater energy intake and thus to greater rates of obesity.^[14][15]

Sugar consumption

Sweetened drinks containing either sucrose alone or sucrose in combination with fructose appear to lead to weight gain due to increase energy intake.^[16]

Social policy and change

Agricultural policy and techniques in the United States and Europe have led to lower food prices. In the United States, subsidization of corn, soy, wheat, and rice through the U.S. farm bill has made the main sources of processed food cheap compared to fruits and vegetables.^[17]

Metabolism

Evidence does not support the commonly expressed view that some obese people eat little yet gain weight due to a slow metabolism. On average obese people have a greater energy expenditure than normal weight or thin people.^[18] This is because it takes more energy to maintain an increased body mass.^[19] Obese people also underreport how much food they consume compared to those of normal weight.^[20] Tests of human subjects carried out in a calorimeter support this conclusion.^[21]

See Also

• List of countries by dietary calorie intake
• Criticism of fast food

References

1. ^ ^{a b} "Compendium of food and agriculture indicators - 2006". Food and Agriculture Organization of the United Nations. http://www.fao.org/statistics/compendium_2006/list.asp. Retrieved February 18, 2009. 
2. ^ "Compendium of food and agriculture indicators - 2006". FAO. http://www.fao.org/statistics/compendium_2006/concepts.asp. Retrieved February 18, 2009. ^{[dead link]}
3. ^ "Compendium of food and agriculture indicators - 2006". UN Food and Agriculture Organization. Archived from the original on August 2, 2008. http://web.archive.org/web/20080802131149/http://www.fao.org/statistics/compendium_2006/list.asp. Retrieved January 10, 2009. 
4. ^ ^{a b} "Calories per capita per day" (gif). UN Food and Agriculture Organization. http://www.fao.org/statistics/chartroom/chart.asp?image=img/charts/fbs/chart08.gif. Retrieved January 10, 2009. ^{[dead link]}
5. ^ "www.fao.org". UN Food and Agriculture Organization. http://www.fao.org/ES/ess/yearbook/vol_1_2/pdf/United-States-of-America.pdf. Retrieved January 10, 2009. 
6. ^ "USDA: frsept99b". USDA. http://www.scribd.com/doc/1470965/USDA-frsept99b. Retrieved January 10, 2009. 
7. ^ "In the Long Run" (pdf). USDA. http://www.ers.usda.gov/Amberwaves/April04/pdf/indicators.pdf. Retrieved February 17, 2009. 
8. ^ ^{a b c} Wright JD, Kennedy-Stephenson J, Wang CY, McDowell MA, Johnson CL (February 2004). "Trends in intake of energy and macronutrients—United States, 1971–2000". MMWR Morb Mortal Wkly Rep 53 (4): 80–2. PMID 14762332. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5304a3.htm. 
9. ^ Caballero B (2007). "The global epidemic of obesity: An overview". Epidemiol Rev 29: 1–5. doi:10.1093/epirev/mxm012. PMID 17569676. 
10. ^ Rosenheck R (November 2008). "Fast food consumption and increased caloric intake: a systematic review of a trajectory towards weight gain and obesity risk". Obes Rev 9 (6): 535–47. doi:10.1111/j.1467-789X.2008.00477.x. PMID 18346099. 
11. ^ Lin BH, Guthrie J and Frazao E (1999). "Nutrient contribution of food away from home". In Frazão E. Agriculture Information Bulletin No. 750: America's Eating Habits: Changes and Consequences. Washington, DC: US Department of Agriculture, Economic Research Service. pp. 213–239. http://www.ers.usda.gov/publications/aib750/. 
12. ^ Malik VS, Schulze MB, Hu FB (August 2006). "Intake of sugar-sweetened beverages and weight gain: a systematic review". Am. J. Clin. Nutr. 84 (2): 274–88. PMID 16895873. http://www.ajcn.org/cgi/pmidlookup?view=long&pmid=16895873. 
13. ^ Olsen NJ, Heitmann BL (January 2009). "Intake of calorically sweetened beverages and obesity". Obes Rev 10 (1): 68–75. doi:10.1111/j.1467-789X.2008.00523.x. PMID 18764885. 
14. ^ Ledikwe JH, Ello-Martin JA, Rolls BJ (April 2005). "Portion sizes and the obesity epidemic". J. Nutr. 135 (4): 905–9. PMID 15795457. 
15. ^ Steenhuis IH, Vermeer WM (2009). "Portion size: review and framework for interventions". Int J Behav Nutr Phys Act 6: 58. doi:10.1186/1479-5868-6-58. PMC 2739837. PMID 19698102. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2739837. 
16. ^ Tappy, L; Lê, KA (2010 Jan). "Metabolic effects of fructose and the worldwide increase in obesity". Physiological reviews 90 (1): 23–46. doi:10.1152/physrev.00019.2009. PMID 20086073. 
17. ^ Pollan, Michael (22 April 2007). "You Are What You Grow". New York Times. http://www.nytimes.com/2007/04/22/magazine/22wwlnlede.t.html?ex=1186027200&en=bbe0f6a2c10e3b3c&ei=5070. Retrieved 2007-07-30. 
18. ^ Kushner, Robert (2007). Treatment of the Obese Patient (Contemporary Endocrinology). Totowa, NJ: Humana Press. pp. 158. ISBN 1-59745-400-1. http://books.google.com/?id=vWjK5etS7PMC&pg=PA121&lpg=PA121&dq=measurement+of+metabolism+in+obese+Bessesen. Retrieved April 5, 2009. 
19. ^ Adams JP, Murphy PG (July 2000). "Obesity in anaesthesia and intensive care". Br J Anaesth 85 (1): 91–108. doi:10.1093/bja/85.1.91. PMID 10927998. http://bja.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=10927998. 
20. ^ Peter G. Kopelman, Ian D. Caterson, Michael J. Stock, William H. Dietz (2005). Clinical obesity in adults and children: In Adults and Children. Blackwell Publishing. ISBN 140-511672-2. http://books.google.com/?id=u7RvldSr5M0C. 
21. ^ "mdPassport". http://www.medicalpost.com/therapeutics/nutrition/article.jsp?content=20080818_121920_25640. Retrieved December 31, 2008.