Dieting is the practice of eating food in a regulated and supervised fashion to decrease, maintain, or increase body weight, or to prevent and treat diseases, such as diabetes. A restricted diet is often used by those who are overweight or obese, sometimes in combination with physical exercise, to reduce body weight. Some people follow a diet to gain weight (usually in the form of muscle). Diets can also be used to maintain a stable body weight and improve health.
Diets to promote weight loss can be categorized as: low-fat, low-carbohydrate, low-calorie, very low calorie and more recently flexible dieting. A meta-analysis of six randomized controlled trials found no difference between low-calorie, low-carbohydrate, and low-fat diets, with a 2–4 kilogram weight loss over 12–18 months in all studies. At two years, all calorie-reduced diet types cause equal weight loss irrespective of the macronutrients emphasized. In general, the most effective diet is any which reduces calorie consumption.
A study published in American Psychologist found that short-term dieting involving "severe restriction of calorie intake" does not lead to "sustained improvements in weight and health for the majority of individuals". Other studies have found that the average individual maintains some weight loss after dieting. Weight loss by dieting, while of benefit to those classified as unhealthy, may slightly increase the mortality rate for individuals who are otherwise healthy.
The first popular diet was "Banting", named after William Banting. In his 1863 pamphlet, Letter on Corpulence, Addressed to the Public, he outlined the details of a particular low-carbohydrate, low-calorie diet that had led to his own dramatic weight loss.
One of the first dietitians was the English doctor George Cheyne. He himself was tremendously overweight and would constantly eat large quantities of rich food and drink. He began a meatless diet, taking only milk and vegetables, and soon regained his health. He began publicly recommending his diet for everyone suffering from obesity. In 1724, he wrote An Essay of Health and Long Life, in which he advises exercise and fresh air and avoiding luxury foods.
The Scottish military surgeon, John Rollo, published Notes of a Diabetic Case in 1797. It described the benefits of a meat diet for those suffering from diabetes, basing this recommendation on Matthew Dobson's discovery of glycosuria in diabetes mellitus. By means of Dobson's testing procedure (for glucose in the urine) Rollo worked out a diet that had success for what is now called type 2 diabetes.
The first popular diet was "Banting", named after the English undertaker William Banting. In 1863, he wrote a booklet called Letter on Corpulence, Addressed to the Public, which contained the particular plan for the diet he had successfully followed. His own diet was four meals per day, consisting of meat, greens, fruits, and dry wine. The emphasis was on avoiding sugar, sweet foods, starch, beer, milk and butter. Banting’s pamphlet was popular for years to come, and would be used as a model for modern diets. The pamphlet's popularity was such that the question "Do you bant?" referred to his method, and eventually to dieting in general. His booklet remains in print as of 2007.
The first weight-loss book to promote calorie counting, and the first weight-loss book to become a bestseller, was the 1918 Diet and Health: With Key to the Calories by American physician and columnist Lulu Hunt Peters.
Low-fat diets involve the reduction of the percentage of fat in one's diet. Calorie consumption is reduced because less fat is consumed. Diets of this type include NCEP Step I and II. A meta-analysis of 16 trials of 2–12 months' duration found that low-fat diets (without intentional restriction of caloric intake) resulted in average weight loss of 3.2 kg (7.1 lb) over habitual eating.
Low-calorie diets usually produce an energy deficit of 500–1,000 calories per day, which can result in a 0.5 to 1 kilogram (1.1 to 2.2 pounds) weight loss per week. One of the most commonly used low-calorie diets is Weight Watchers. The National Institutes of Health reviewed 34 randomized controlled trials to determine the effectiveness of low-calorie diets. They found that these diets lowered total body mass by 8% in the short term, over 3–12 months. Women doing low-calorie diets should have at least 1,000 calories per day and men should have approximately 1,200 calories per day. These caloric intake values vary depending on additional factors, such as age and weight.
Very low calorie diets provide 200–800 calories per day, maintaining protein intake but limiting calories from both fat and carbohydrates. They subject the body to starvation and produce an average loss of 1.5–2.5 kg (3.3–5.5 lb) per week. "2-4-6-8", a popular diet of this variety, follows a four-day cycle in which only 200 calories are consumed the first day, 400 the second day, 600 the third day, 800 the fourth day, and then totally fasting, after which the cycle repeats. These diets are not recommended for general use as they are associated with adverse side effects such as loss of lean muscle mass, increased risks of gout, and electrolyte imbalances. People attempting these diets must be monitored closely by a physician to prevent complications.
Religious prescription may be a factor in motivating people to adopt a specific restrictive diet. For example, the Biblical Book of Daniel (1:2-20, and 10:2-3) refers to a 10- or 21-day avoidance of foods (Daniel Fast) declared unclean by God in the laws of Moses. In modern versions of the Daniel Fast, food choices may be limited to whole grains, fruits, vegetables, pulses, nuts, seeds and oil. The Daniel Fast resembles the vegan diet in that it excludes foods of animal origin. The passages strongly suggest that the Daniel Fast will promote good health and mental performance.
Fasting is practiced in various religions. Examples include Lent in Christianity; Yom Kippur, Tisha B'av, Fast of Esther, Tzom Gedalia, the Seventeenth of Tamuz, and the Tenth of Tevet in Judaism. Muslims refrain from eating during the hours of daytime for one month, Ramadan, every year.
Details of fasting practices differ. Eastern Orthodox Christians fast during specified fasting seasons of the year, which include not only the better-known Great Lent, but also fasts on every Wednesday and Friday (except on special holidays), together with extended fasting periods before Christmas (the Nativity Fast), after Easter (the Apostles Fast) and in early August (the Dormition Fast). Members of The Church of Jesus Christ of Latter-day Saints (Mormons) generally fast for 24 hours on the first Sunday of each month. Like Muslims, they refrain from all drinking and eating unless they are children or are physically unable to fast. Fasting is also a feature of ascetic traditions in religions such as Hinduism and Buddhism. Mahayana traditions that follow the Brahma's Net Sutra may recommend that the laity fast "during the six days of fasting each month and the three months of fasting each year" [Brahma's Net Sutra, minor precept 30]. Members of the Baha'i Faith observe a Nineteen Day Fast from sunrise to sunset during March each year.
Weight loss diets that manipulate the proportion of macronutrients (low-fat, low-carbohydrate, etc.) have been shown to be no more effective than diets that maintain a typical mix of foods with smaller portions and perhaps some substitutions (e.g. low-fat milk, or less salad dressing). Extreme diets may, in some cases, lead to malnutrition.
The Dietary Guidelines for Americans is a set of recommendations about a healthy diet written for policy makers, nutrition scientists, and dieticians and other clinicians, produced by the US Department of Agriculture, in concert with the US Department of Health and Human Services and quintannually-revised. The current guidelines are written for the period 2015 - 2020 and were used to produce the MyPlate recommendations on a healthy diet for the general public.
One of the most important things to take into consideration when either trying to lose or put on weight is output versus input. It is important to know the amount of energy your body is using every day, so that your intake fits the needs of one's personal weight goal. Someone wanting to lose weight would want a smaller energy intake than what they put out. There is increasing research-based evidence that low-fat vegetarian diets consistently lead to healthy weight loss and management, a decrease in diabetic symptoms as well as improved cardiac health.
How the body eliminates fatEdit
When the body is expending more energy than it is consuming (e.g. when exercising), the body's cells rely on internally stored energy sources, such as complex carbohydrates and fats, for energy. The first source to which the body turns is glycogen (by glycogenolysis). Glycogen is a complex carbohydrate, 65% of which is stored in skeletal muscles and the remainder in the liver (totaling about 2,000 kcal in the whole body). It is created from the excess of ingested macronutrients, mainly carbohydrates. When glycogen is nearly depleted, the body begins lipolysis, the mobilization and catabolism of fat stores for energy. In this process fats, obtained from adipose tissue, or fat cells, are broken down into glycerol and fatty acids, which can be used to generate energy. The primary by-products of metabolism are carbon dioxide and water; carbon dioxide is expelled through the respiratory system.
Weight loss groupsEdit
Some weight loss groups aim to make money, others work as charities. The former include Weight Watchers and Peertrainer. The latter include Overeaters Anonymous, TOPS Club and groups run by local organizations.
These organizations' customs and practices differ widely. Some groups are modelled on twelve-step programs, while others are quite informal. Some groups advocate certain prepared foods or special menus, while others train dieters to make healthy choices from restaurant menus and while grocery-shopping and cooking.
A 2008 study published in the American Journal of Preventive Medicine showed that dieters who kept a daily food diary (or diet journal), lost twice as much weight as those who did not keep a food log, suggesting that if a person records their eating, they are more aware of what they consume and therefore eat fewer calories.
Possible weight loss effects of drinking water prior to mealsEdit
A 2009 review found that existing limited evidence suggested that encouraging water consumption and substituting energy-free beverages for energy-containing beverages (i.e., reducing caloric intake) may facilitate weight management. A 2009 article found that drinking 500 ml of water prior to meals for a 12-week period resulted in increased long-term weight reduction. (References given in main article.)
Fasting is when there is a long time interval between the meals. In dieting, fasting is not recommended, instead, having small portions of food after small intervals is encouraged. Lengthy fasting can also be dangerous due to the risk of malnutrition and should be carried out only under medical supervision. During prolonged fasting or very low calorie diets the reduction of blood glucose, the preferred energy source of the brain, causes the body to deplete its glycogen stores. Once glycogen is depleted the body begins to fuel the brain using ketones, while also metabolizing body protein (including but not limited to skeletal muscle) to be used to synthesize sugars for use as energy by the rest of the body. Most experts believe that a prolonged fast can lead to muscle wasting, although some dispute this. The use of short-term fasting, or various forms of intermittent fasting have been used as a form of dieting to circumvent this issue.
Crash dieting can highly be dangerous because it can cause various kind of issues for the human body. The basic concept of crash dieting is to miss 1 or more than 1 food groups completely. Crash dieting can make you loss weight but that weight loss is due to the lack of proper nutrition which can be a real problem in many ways. Crash diet is a recipe of disaster. Weight loss can be possible in many natural ways without putting your life at risk.
While there are studies that show the health and medical benefits of weight loss, a study in 2005 of around 3000 Finns over an 18-year period showed that weight loss from dieting can result in increased mortality, while those who maintained their weight fared the best. Similar conclusion is drawn by other studies, and although other studies suggest that intentional weight loss has a small benefit for individuals classified as unhealthy, it is associated with slightly increased mortality for healthy individuals and the slightly overweight but not obese. This may reflect the loss of subcutaneous fat and beneficial mass from organs and muscle in addition to visceral fat when there is a sudden and dramatic weight loss.
Low carbohydrate versus low fatEdit
Low-carbohydrate and low-fat diets perform similarly in the long term as weight maintenance depends on calorie intake, not macronutrient ration.
Low glycemic indexEdit
"The glycemic index (GI) factor is a ranking of foods based on their overall effect on blood sugar levels. The diet based around this research is called the Low GI diet. Low glycemic index foods, such as lentils, provide a slower, more consistent source of glucose to the bloodstream, thereby stimulating less insulin release than high glycemic index foods, such as white bread."
The glycemic load is "the mathematical product of the glycemic index and the carbohydrate amount".
- Diet 1 and 2 were high carbohydrate (55% of total energy intake)
- Diet 1 was high-glycemic index
- Diet 2 was low-glycemic index
- Diet 3 and 4 were high protein (25% of total energy intake)
- Diet 3 was high-glycemic index
- Diet 4 was low-glycemic index
Diets 2 and 3 lost the most weight and fat mass; however, low density lipoprotein fell in Diet 2 and rose in Diet 3. Thus the authors concluded that the high-carbohydrate, low-glycemic index diet was the most favorable.
A meta-analysis by the Cochrane Collaboration concluded that low glycemic index or low glycemic load diets led to more weight loss and better lipid profiles. However, the Cochrane Collaboration grouped low glycemic index and low glycemic load diets together and did not try to separate the effects of the load versus the index.
- Strychar I (January 2006). "Diet in the management of weight loss". CMAJ. 174 (1): 56–63. doi:10.1503/cmaj.045037. PMC 1319349. PMID 16389240.
- Sacks FM, Bray GA, Carey VJ, et al. (February 2009). "Comparison of Weight-Loss Diets with Different Compositions of Fat, Protein, and Carbohydrates". N. Engl. J. Med. 360 (9): 859–73. doi:10.1056/NEJMoa0804748. PMC 2763382. PMID 19246357.
- Guth, Eve (3 September 2014). "Healthy Weight Loss". JAMA. 312 (9): 974. doi:10.1001/jama.2014.10929. PMID 25182116.
- Mann, T; Tomiyama, AJ; Westling, E; Lew, AM; Samuels, B; Chatman, J (April 2007). "Medicare's search for effective obesity treatments: diets are not the answer". The American Psychologist. 62 (3): 220–33. CiteSeerX 10.1.1.666.7484. doi:10.1037/0003-066x.62.3.220. PMID 17469900.
In sum, there is little support for the notion that diets ["severely restricting one’s calorie intake"] lead to lasting weight loss or health benefits.
- Anderson, James; Elizabeth C Konz; Robert C Frederich; Constance L Wood (November 2001). "Long-term weight-loss maintenance: a meta-analysis of US studies". The American Journal of Clinical Nutrition. 74 (5): 579–584. doi:10.1093/ajcn/74.5.579. PMID 11684524. Retrieved 22 December 2013.
- Bacon L, Aphramor L.; Aphramor (2011). "Weight science: evaluating the evidence for a paradigm shift". Nutr J. 10: 9. doi:10.1186/1475-2891-10-9. PMC 3041737. PMID 21261939.
- Harrington M; Gibson S; Cottrell RC (2009). "A review and meta-analysis of the effect of weight loss on all-cause mortality risk". Nutr Res Rev. 22 (1): 93–108. doi:10.1017/S0954422409990035. PMID 19555520.
- Kendall Powell (31 May 2007). "The Two Faces of Fat". Nature. 447 (7144): 525–7. doi:10.1038/447525a. PMID 17538594.
- Jennifer Petrelli; Kathleen Y. Wolin (2009). Obesity (Biographies of Disease). Westport, Conn: Greenwood. p. 11. ISBN 978-0-313-35275-1.
- "The Ethics of Diet - A Catena". Retrieved 17 December 2012.
- Elliott Proctor Joslin (2005). Joslin's Diabetes Mellitus: Edited by C. Ronald Kahn ... [et Al.]. Lippincott Williams & Wilkins. p. 3. ISBN 978-0-7817-2796-9. Retrieved 20 June 2013.
- Laurence D. Chalem (5 September 2009). Essential Diabetes Leadership. Laurence Chalem. p. 39. ISBN 978-1-4392-4566-8. Retrieved 20 June 2013.
- Chisholm, Hugh, ed. (1911). Encyclopædia Britannica. 7 (11th ed.). Cambridge University Press. pp. 192–193. .
- Groves, PhD, Barry (2002). "WILLIAM BANTING: The Father of the Low-Carbohydrate Diet". Second Opinions. Retrieved 26 December 2007.
- Banting, William (2005) . Letter on Corpulence. USA: New York: Cosimo Classics. pp. 64 pages. ISBN 978-1-59605-085-3. Archived from the original on 8 July 2011. Retrieved 28 December 2007.
- See also ISBN 0-9543975-1-7.
- Kawash, Samira (2013). Candy: A Century of Panic and Pleasure. New York: Faber & Faber, Incorporated. pp. 185–189. ISBN 9780865477568.
- White, Ellen G (1938). Counsels on Diet and Foods (PDF). ePub. Archived from the original (PDF) on 4 March 2016. Retrieved 3 May 2014.
- Bloomer, Richard J; Mohammad M Kabir; Robert E Canale; John F Trepanowski; Kate E Marshall; Tyler M Farney; Kelley G Hammond (2010). "Effect of a 21 day Daniel Fast on metabolic and cardiovascular disease risk factors in men and women" (PDF). Lipids in Health and Disease. 9: 94. doi:10.1186/1476-511X-9-94. PMC 2941756. PMID 20815907.
- "History of the Fast". Archived from the original on 27 December 2014. Retrieved 14 February 2016.
- Schooff, Michael (February 2003). "Cochrane for Clinicians: Are Low-Fat Diets Better than Other Weight-Reducing Diets in Achieving Long-Term Weight Loss? - American Family Physician". American Family Physician. 67 (3): 507–8. PMID 12588072.
- Trapp, Caroline B.; Barnard, Neal D. (1 April 2010). "Usefulness of vegetarian and vegan diets for treating type 2 diabetes". Current Diabetes Reports. 10 (2): 152–158. doi:10.1007/s11892-010-0093-7. ISSN 1539-0829. PMID 20425575.
- Ornish, D.; Brown, S. E.; Scherwitz, L. W.; Billings, J. H.; Armstrong, W. T.; Ports, T. A.; McLanahan, S. M.; Kirkeeide, R. L.; Brand, R. J. (21 July 1990). "Can lifestyle changes reverse coronary heart disease? The Lifestyle Heart Trial". Lancet. 336 (8708): 129–133. doi:10.1016/0140-6736(90)91656-u. ISSN 0140-6736. PMID 1973470.
- O’Rourke, Brian; Cortassa, Sonia; Aon, Miguel A. (1 October 2005). "Mitochondrial Ion Channels: Gatekeepers of Life and Death". Physiology. 20 (5): 303–315. doi:10.1152/physiol.00020.2005. ISSN 1548-9213. PMC 2739045. PMID 16174870.
- Hellmich, Nanci (8 July 2008). "Using food diaries doubles weight loss, study shows". USA Today. Retrieved 1 May 2010.
- Sørensen TI, Rissanen A, Korkeila M, Kaprio J (2005). "Intention to Lose Weight, Weight Changes, and 18-y Mortality in Overweight Individuals without Co-Morbidities". PLoS Medicine. 2 (6, e171): e171. doi:10.1371/journal.pmed.0020171. PMC 1160579. PMID 15971946.
- Ingram DD, Mussolino ME.; Mussolino (2010). "Weight loss from maximum body weight and mortality: the Third National Health and Nutrition Examination Survey Linked Mortality File". Int J Obes. 34 (6): 1044–1050. doi:10.1038/ijo.2010.41. PMID 20212495.
- Churuangsuk C, Kherouf M, Combet E, Lean M (2018). "Low-carbohydrate diets for overweight and obesity: a systematic review of the systematic reviews". Obes Rev (Systematic review). 19 (12): 1700–1718. doi:10.1111/obr.12744. PMID 30194696.
- Thomas, Diana; Elliott, Elizabeth J.; Baur, Louise (31 July 2006). Written at University of Sydney, Children's Hospital at Westmead, CEBPGAN (Centre for Evidence Based Paediatrics Gastroenterology and Nutrition. Thomas, Diana (ed.). "Low glycaemic index or low glycaemic load diets for overweight and obesity" (PDF). Cochrane Database of Systematic Reviews. USA (published 18 July 2007). 3 (3): CD005105. doi:10.1002/14651858.CD005105.pub2. PMID 17636786.
- Jenkins, D.J.; Wolever, T.M.; Taylor, R.H.; Barker, H.; Fielden, H.; Baldwin, J.M.; Bowling, A.C.; Newman, H.C.; et al. (March 1981). "Glycemic index of foods: a physiological basis for carbohydrate exchange" (PDF). American Journal of Clinical Nutrition. 34 (3): 362–6. doi:10.1093/ajcn/34.3.362. PMID 6259925.
- Brand-Miller, Janette Cecile; Thomas, M.; Swan, V.; Ahmad, Z.I.; Petocz, P.; Colagiuri, S. (2003). Written at Human Nutrition Unit, School of Molecular and Microbial Biosciences, University of Sydney, Sydney, NSW, Australia. "Physiological Validation of the Concept of Glycemic Load in Lean Young Adults" (PDF). The Journal of Nutrition. USA (published September 2003). 133 (9): 2728–32. doi:10.1093/jn/133.9.2728. PMID 12949357.
- McMillan-Price, J.; Petocz, P.; Atkinson, F.; O'neill, K.; Samman, S.; Steinbeck, K.; Caterson, I.; Brand-Miller, Janette Cecile (2006). Written at Human Nutrition Unit, University of Sydney, Sydney, Australia. "Comparison of 4 Diets of Varying Glycemic Load on Weight Loss and Cardiovascular Risk Reduction in Overweight and Obese Young Adults: A Randomized Controlled Trial" (PDF). Archives of Internal Medicine. USA (published 24 July 2006). 166 (14): 1466–75. doi:10.1001/archinte.166.14.1466. PMID 16864756.
- Thomas DE, Elliott E, Baur L (2007). "Low glycaemic index or low glycaemic load diets for overweight and obesity". Cochrane Database of Systematic Reviews (3): CD005105. doi:10.1002/14651858.CD005105.pub2. PMID 17636786.
- American Dietetic Association (2003). "Position Paper on Vegetarian Diets". J Am Diet Assoc. 103 (6): 748–765. doi:10.1053/jada.2003.50142. PMID 12778049.
- Cheraskin Emmanuel (1993). "The Breakfast/Lunch/Dinner Ritual". Journal of Orthomolecular Medicine. 8 (1).
- Dansinger, M. L., Gleason, J. L., Griffith, J. L., et al., "One Year Effectiveness of the Atkins, Ornish, Weight Watchers, and Zone Diets in Decreasing Body Weight and Heart Disease Risk", Presented at the American Heart Association Scientific Sessions, Orlando, Florida, 12 November 2003.
- Schwartz, Hillel. Never Satisfied: A Cultural History of Diets, Fantasies, and Fat. New York: Free Press/Macmillan, 1986.
|Wikiquote has quotations related to: Diet|
|Wikimedia Commons has media related to Diet.|