No-carbohydrate diet

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A no-carbohydrate diet (no-carb diet, zero carb diet) excludes dietary consumption of all carbohydrates (including dietary fiber) and suggests fat as the main source of energy with sufficient protein. A no-carbohydrate diet may be ketogenic, which means it causes the body to go into a state of ketosis, converting dietary fat and body fat into ketone bodies which are used to fuel parts of the body that do not oxidize fat for energy, especially the brain. Some bodily organs and parts of the brain still require glucose, which is tightly regulated by the liver and adequately supplied by gluconeogenesis or by converting glycerol from the breakdown of triglycerides. A no-carbohydrate diet may use mainly animal source foods and may include a high saturated fat intake, though this is not prescriptive of the diet, which, by definition, only restricts carbohydrate intake.

History[edit]

An early proponent of an all animal-based diet was Icelandic-Canadian explorer Vilhjalmur Stefansson (1879–1962), who lived with the Inuit for some time and witnessed their diet as essentially consisting of meat and fish, with very few carbohydrates—just berries during the summer. However, the accuracy of his analysis has been since called into question, as the Inuit diet has not been shown to be a ketogenic diet and roughly 15-20% of its calories are from carbohydrates, largely from the glycogen found in the raw meats.[1][2][3] Stefansson and a friend later volunteered for a one-year experiment at Bellevue Hospital Center in New York City to prove he could thrive on a diet of nothing but meat, meat fat, and internal organs of animals.[4] His progress was closely monitored and experiments were done on his health throughout the year. At the end of the year, he did not show any symptoms of ill health; he did not develop scurvy, which many scientists had expected to manifest itself only a few months into the diet due to the lack of vitamin C in muscle meat. However, Stefansson and his partner did not eat just muscle meat but also fat, raw brain,[5] raw liver (a significant source of vitamin C and others), and other varieties of offal.[6] There is some question as to amount - if any - of raw brain, raw liver, or other organ/offal eating by either Stefansson or his friend during the Study as reports indicate a vast majority of meat consumed as being mutton, with that being almost all fatty cuts.[citation needed]

Carbohydrate-restricted diets gained great popularity, particularly in the case of the Atkins Diet which emerged in 1972, thanks to Robert Atkins. While his diet is not a zero-carbohydrate diet, it does reduce carbohydrate intake to a ketogenic level in its initial stages (20 grams daily in induction; weekly increase of 5 grams thereafter), allowing followers to take advantage of the fat-burning mechanism that is ketosis. According to Atkins, this nutritional approach is more effective for weight loss than a low-fat, "high-carbohydrate diet", although there has always been much controversy and great dispute amongst healthcare professionals concerning drastic carbohydrate restriction.[7]

See also[edit]

References[edit]

  1. ^ Peter Heinbecker (1928). "Studies on the Metabolism of Eskimos" (PDF). J. Biol. Chem. 80 (2): 461–475. Retrieved 2014-04-07. 
  2. ^ A.C. Corcoran; M. Rabinowitch (1937). "A Study of the Blood Lipoids and Blood Protein in Canadian Eastern Arctic Eskimos". Biochem. J. 31 (3): 343–348. doi:10.1042/bj0310343. PMC 1266943Freely accessible. PMID 16746345. 
  3. ^ Kang-Jey Ho; Belma Mikkelson; Lena A. Lewis; Sheldon A. Feldman; C. Bruce Taylor (1972). "Alaskan Arctic Eskimo: responses to a customary high fat diet" (PDF). Am J Clin Nutr. 25 (8): 737–745. doi:10.1093/ajcn/25.8.737. Retrieved 2014-04-07. 
  4. ^ McClellan WS, Du Bois EF (1930). "Clinical calorimetry. XLV. Prolonged meat diets with a study on kidney function and ketosis" (PDF). J. Biol. Chem. 87 (3): 651–668. 
  5. ^ McCellan, Walter (1930). Clinical Calorimetry. Russel Sage Institute of Pathology. p. 655. 
  6. ^ McCellan, Walter (1930). Clinical Calorimetry. Russel Sage Institute of Pathology. p. 655. 
  7. ^ "No Carb Diet Plan". CBS Money Watch. Retrieved 2010-08-26.

Further reading[edit]