Protein-sparing modified fast (diet)

{{Short description|Type of diet}} {{Use dmy dates|date=May 2020}} A '''protein-sparing modified fast''' or '''PSMF diet''' is a type of a [[very-low-calorie diet]] (<800 kcal per day) with a high proportion of protein calories and simultaneous restriction of carbohydrate and fat.<ref>{{Citation|last1=Bal|first1=Bikram S.|title=Nutritional Requirements of the Critically Ill Obese Patient|date=2012-04-19|work=Critical Care Management of the Obese Patient|pages=186–194|publisher=Wiley-Blackwell|isbn=978-1-119-96208-3|last2=Finelli|first2=Frederick C.|last3=Koch|first3=Timothy R.|doi=10.1002/9781119962083.ch21}}</ref> It includes a [[protein (nutrient)|protein]] component, [[fluid balance|fluids]], and [[multivitamin|vitamin and mineral supplementation]].<ref name=Ch2014>{{cite journal|last1=Chang|first1=J|last2=Kashyap|first2=SR|date=September 2014|title=The protein-sparing modified fast for obese patients with type 2 diabetes: what to expect.|journal=Cleveland Clinic Journal of Medicine|volume=81|issue=9|pages=557–65|doi=10.3949/ccjm.81a.13128|pmid=25183847|s2cid=4345893|doi-access=free}}</ref><ref name="cenc">{{cite encyclopedia|url=https://books.google.com/books?id=ZWmRAgAAQBAJ&pg=PA160|title=Linn, Robert (1933–)|author=Gilman SL|encyclopedia=Diets and Dieting: A Cultural Encyclopedia|publisher=Routledge|year=2007|isbn=978-1-135-87068-3|page=160}}</ref>

PSMF diets can last for up to 6 months, followed by a gradual increase in calories over 6–8 weeks.<ref name=Ch2014/>

==Description==

A PSMF attempts to spare the dieter the health risks of a complete fast by introducing the minimum amount of protein necessary to prevent muscle-wasting effects, while still eliminating fats and carbohydrates.<ref>{{cite journal|title=The Protein-Sparing Modified Fast Diet|author=Cleveland Clinic Foundation|journal=Global Pediatric Health|date=22 January 2016|volume=3|article-number=2333794X15623245|doi=10.1177/2333794X15623245|pmid=27335996|pmc=4784653}}</ref> Typically, depending on activity level, 0.8–1.2 g of protein per pound of [[lean body mass]] (not total body weight) is consumed. Protein beyond this minimum amount is also eliminated, as the body would use it for additional energy by increasing [[gluconeogenesis]].<ref name="pmid23613553">{{cite journal| author=Nuttall FQ, Gannon MC| title=Dietary protein and the blood glucose concentration. | journal=Diabetes | year= 2013 | volume= 62 | issue= 5 | pages= 1371–2 | pmid=23613553 | doi=10.2337/db12-1829 | pmc=3636610 }}</ref> Further lean body mass (muscle, organs, etc.) can be spared through resistance training.<ref>{{cite journal|last1=Manninen|first1=Anssi|title=Very-low-carbohydrate diets and preservation of muscle mass|pmc=1373635|pmid=16448570|doi=10.1186/1743-7075-3-9|volume=3|year=2006|journal=Nutr Metab (Lond)|page=9 |doi-access=free }}</ref><ref>{{cite journal|last1=Bryner|first1=Randy|title=Effects of Resistance vs. Aerobic Training Combined With an 800 Calorie Liquid Diet on Lean Body Mass and Resting Metabolic Rate |url=https://www.researchgate.net/publication/13093090|journal=Journal of the American College of Nutrition|year=1999|volume=18|issue=2|pages=115–121|doi=10.1080/07315724.1999.10718838|pmid=10204826|s2cid=25528612 |access-date=10 July 2017}}</ref>

==History== ===The Last Chance Diet===

The concept of "protein-sparing modified fast" (PSMF) was described by [[George L. Blackburn|George Blackburn]] in the early 1970s as an intensive weight-loss diet designed to mitigate the harms associated with protein-calorie malnutrition<ref>{{cite web|url=https://praktisch-abnehmen.de/intervallfasten-16-8/|title=Protein-calorie malnutrition|author=praktischabnehmen|date=26 November 2021|language=de}}</ref> and nitrogen losses induced by either acute illness or hypocaloric diets in patients with obesity, in order to adapt the patient's metabolism sufficiently to use endogenous fat stores as well as to preserve the protein contained in the body cell mass.<ref>{{Cite journal|last1=Blackburn|first1=C. L.|last2=Flatt|first2=J. P.|last3=Clowes|first3=G. H. A.|last4=Oʼdonnell|first4=T. F.|last5=Hensle|first5=T. E.|date=May 1973|title=Protein Sparing Therapy during Periods of Starvation with Sepsis or Trauma|journal=Annals of Surgery|volume=177|issue=5|pages=588–94|doi=10.1097/00000658-197305000-00012|pmid=4634108|pmc=1355601|issn=0003-4932}}</ref><ref name=":3">{{Cite journal|last1=Thomas|first1=Dylan D.|last2=Istfan|first2=Nawfal W.|last3=Bistrian|first3=Bruce R.|last4=Apovian|first4=Caroline M.|date=February 2018|title=Protein sparing therapies in acute illness and obesity: a review of George Blackburn's contributions to nutrition science|journal=Metabolism|volume=79|pages=83–96|doi=10.1016/j.metabol.2017.11.020|pmid=29223678|pmc=5809291}}</ref>

The "liquid protein" PSMF diet described in the book ''The Last Chance Diet'' in 1976,<ref>{{Cite journal|last=Engelman|first=Ralph|date=July 1989|title=Joseph C. Goulden. Fit to Print: A.M. Rosenthal and His Times.|journal=American Journalism|volume=6|issue=3|pages=202–204|doi=10.1080/08821127.1989.10731199|issn=0882-1127}}</ref> motivates that the liquid protein diets of varying composition became widely popular. Three years later, in 1979, Isner published a report of 17 deaths associated with liquid protein [[Very-low-calorie diet|VLCD]], due to heart-related causes.<ref>{{Cite journal|last1=Isner|first1=J M|last2=Sours|first2=H E|last3=Paris|first3=A L|last4=Ferrans|first4=V J|last5=Roberts|first5=W C|date=December 1979|title=Sudden, unexpected death in avid dieters using the liquid-protein-modified-fast diet. Observations in 17 patients and the role of the prolonged QT interval.|journal=Circulation|volume=60|issue=6|pages=1401–1412|doi=10.1161/01.CIR.60.6.1401|pmid=498466|issn=0009-7322|doi-access=free}}</ref> These serious effects caused a substantial concern about the safety of clinical use of PSMF and VLCD. As a result, a review was published that highlighted the differences between these liquid protein diets, arguing that the fatal diets typically used hydrolyzed collagen (gelatin) supplemented with the amino acid [[tryptophan]] for protein but that this omitted the other 8 [[Essential amino acid|essential amino acids]]; it further emphasized the importance of close medical monitoring during the fast and refeeding periods.<ref>{{Cite journal|last=Bistrian|first=Bruce R.|date=1978-11-17|title=Clinical Use of a Protein-Sparing Modified Fast|journal=JAMA: The Journal of the American Medical Association|volume=240|issue=21|pages=2299–302|doi=10.1001/jama.1978.03290210081040|pmid=702762|issn=0098-7484|url=https://gwern.net/doc/biology/1978-bistrian.pdf}}</ref>

===Modern PSMF diets=== Instead of hydrolyzed collagen, modern medically supervised PSMF diets use more complete liquid protein sources and/or include foods of higher [[biological value]], such as meat, fish, eggs, cheese, and/or tofu.<ref name=Ch2014 /> PSMF is used as a treatment for highly motivated patients to achieve rapid weight loss and usually is administered for 6 – 16 weeks.<ref name=":3" /><ref>{{cite web|url=https://consultqd.clevelandclinic.org/study-psmf-diet-shown-provide-long-term-weight-loss/|title=Study: PSMF Diet Shown To Provide Long-term Weight Loss|author=Cleveland Clinic Foundation|date=28 March 2018}}</ref>

Before an individual starts a PSMF diet, the individual should also consume specific vitamins minerals and electrolytes daily as long as the diet persists to prevent deficits in other nutrients.<ref name=Ch2014/><ref>{{cite journal|title=The Effect of Starting the Protein-Sparing Modified Fast on Weight Change over 5 years|author=Center for Value-Based Care Research|journal=Journal of General Internal Medicine|date=8 January 2020|volume=35|issue=3|pages=704–710|doi=10.1007/s11606-019-05535-0|pmid=31916212|pmc=7080885}}</ref>. It can also be prudent to consult a doctor about getting an electrocardiogram, to check for signs of heart disease.

==See also==

* [[Atkins diet]]: a low-carbohydrate diet * [[Dukan Diet]]: a high-protein, low-carbohydrate, low-fat diet * [[Fasting]] * [[Intermittent fasting]] * [[Low-carbohydrate diet]] * [[Stillman diet]]: a high-protein, low-carbohydrate, low-fat diet

==References== {{Reflist}}

[[Category:Fasting]] [[Category:Proteins (nutrient)]] [[Category:Fad diets]]

[[fr:Régime protal]] [[nl:Dukan-dieet]] [[pl:Dieta proteinowa]]