Types of fasting[edit | edit source]
Water only fasting[edit | edit source]
As the name implies, this is a type of fasting where only water may be consumed – no other food or beverage is permitted.
Liquid fasting[edit | edit source]
Some fasts include abstaining from solid foods but consuming calorie-containing liquids, such as vegetables juices or broth.
Intermittent fasting[edit | edit source]
In this form of fasting, a person alternates between periods of fasting and non-fasting, with a defined schedule. Intermittent fasting is of interest to researchers for its potential effects on insulin sensitivity and other aspects of health. Popular types of intermittent fasting include: 16:8, 16-hr fast with a 8-hr eating window, 18:6, 18-hr fast with a 6-hr eating window, 20:4, 20-hr fast with a 4-hr eating window. The alternate day fast is a 36 hour fast followed by a 12-hr eating window.
Caloric restriction[edit | edit source]
A calorie restricted (CR) diet reduces calorie intake without malnutrition. It is chronic and does not include a refeeding phase. Most clinical trials of CR aim for 25-30% total calorie reduction. The 5:2 diet is a calorically restricted diet in which 2 days per week one consumes 500-600 calories, and eats normally the remaining 5 week days.
Physiological effects[edit | edit source]
A fast with duration sufficient to deplete the body's glycogen stores, at least 18 hours, increases the blood ketone β-hydroxybutyrate allowing for nutritional ketosis.
Fasting increases autophagy in mice.
The US National Institute on Aging and the National Institute of Diabetes and Digestive and Kidney Diseases conducted the CALERIE (Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy) study using a 2-year CR diet (25% reduction) in non-obese adults (n = 143) compared to an ad libitum group (n =75). The CR group reported improvements in mood and improved sleep quality without adverse effects or immune compromise. There was also improvement in cardiovascular risk factors including C-reactive protein.
Health effects[edit | edit source]
There is no evidence on the benefits or harms of fasting for ME and CFS patients. However, there is a growing body of evidence suggesting possible health benefits of water-only fasting to the microbiome, mitochondria and the immune system, and as a cancer adjuvant.
Immune system[edit | edit source]
Caloric restriction significantly reduced the amount of circulating lipopolysaccharide-binding protein. In vitro, short-term (19 hour) fasting reduced monocyte metabolic and inflammatory activity and drastically reduced the number of circulating monocytes. This effect is thought to be due to redistribution of these cells to the bone marrow. Caloric restriction and intermittent fasting strongly reduced the accumulation of pathogenic monocytes in the central nervous system, reduced monocyte pro-inflammatory activity, and improved disease outcome in a mouse model of multiple sclerosis and in a preclinical model in multiple sclerosis patients.
Chronic fatigue syndrome[edit | edit source]
See also[edit | edit source]
Learn more[edit | edit source]
References[edit | edit source]
- Kraus, William E.; Bhapkar, Manjushri; Huffman, Kim M.; Pieper, Carl F.; Krupa Das, Sai; Redman, Leanne M.; Villareal, Dennis T.; Rochon, James; Roberts, Susan B. (Sep 2019). "2 years of calorie restriction and cardiometabolic risk (CALERIE): exploratory outcomes of a multicentre, phase 2, randomised controlled trial". The Lancet. Diabetes & Endocrinology. 7 (9): 673–683. doi:10.1016/S2213-8587(19)30151-2. ISSN 2213-8595. PMC . PMID 31303390.
- Remely, Marlene; Hippe, Berit; Geretschlaeger, Isabella; Stegmayer, Sonja; Hoefinger, Ingrid; Haslberger, Alexander (May 2015), "Increased gut microbiota diversity and abundance of Faecalibacterium prausnitzii and Akkermansia after fasting: a pilot study", Wiener Klinische Wochenschrift, 127 (9-10): 394–398, doi:10.1007/s00508-015-0755-1, ISSN 1613-7671, PMID 25763563
- Cerqueira, Fernanda M.; Laurindo, Francisco R. M.; Kowaltowski, Alicia J. (Mar 31, 2011), "Mild Mitochondrial Uncoupling and Calorie Restriction Increase Fasting eNOS, Akt and Mitochondrial Biogenesis", PLOS ONE, 6 (3): –18433, doi:10.1371/journal.pone.0018433, ISSN 1932-6203, retrieved Nov 9, 2016
- Cheng, Chia-Wei; Adams, Gregor B.; Perin, Laura; Wei, Min; Zhou, Xiaoying; Lam, Ben S.; Da Sacco, Stefano; Mirisola, Mario; Quinn, David I.; Dorff, Tanya B.; Kopchick, John J.; Longo, Valter D. (Jun 5, 2014), "Prolonged Fasting Reduces IGF-1/PKA to Promote Hematopoietic-Stem-Cell-Based Regeneration and Reverse Immunosuppression", Cell Stem Cell, 14 (6): 810–823, doi:10.1016/j.stem.2014.04.014, ISSN 1934-5909, retrieved Nov 9, 2016
- Lee, Changhan; Raffaghello, Lizzia; Brandhorst, Sebastian; Safdie, Fernando M.; Bianchi, Giovanna; Martin-Montalvo, Alejandro; Pistoia, Vito; Wei, Min; Hwang, Saewon; Merlino, Annalisa; Emionite, Laura; Cabo, Rafael de; Longo, Valter D. (Mar 7, 2012), "Fasting Cycles Retard Growth of Tumors and Sensitize a Range of Cancer Cell Types to Chemotherapy", Science Translational Medicine, 4 (124): 124–27–124ra27, doi:10.1126/scitranslmed.3003293, ISSN 1946-6234, PMID 22323820, retrieved Nov 9, 2016
- Lee, C.; Longo, V. D. (Jul 28, 2011), "Fasting vs dietary restriction in cellular protection and cancer treatment: from model organisms to patients", Oncogene, 30 (30): 3305–3316, doi:10.1038/onc.2011.91, ISSN 0950-9232, retrieved Nov 9, 2016
- Safdie, Fernando M.; Dorff, Tanya; Quinn, David; Fontana, Luigi; Wei, Min; Lee, Changhan; Cohen, Pinchas; Longo, Valter D. (Dec 31, 2009), "Fasting and cancer treatment in humans: A case series report", Aging (Albany NY), 1 (12): 988–1007, ISSN 1945-4589, PMID 20157582, retrieved Nov 9, 2016
- Zhang, Chenhong; Li, Shoufeng; Yang, Liu; Huang, Ping; Li, Wenjun; Wang, Shengyue; Zhao, Guoping; Zhang, Menghui; Pang, Xiaoyan; Yan, Zhen; Liu, Yong; Zhao, Liping (Jul 16, 2013), "Structural modulation of gut microbiota in life-long calorie-restricted mice", Nature Communications, 4: 2163, doi:10.1038/ncomms3163, ISSN 2041-1723, retrieved Nov 9, 2016
- Cignarella, Francesca; Cantoni, Claudia; Ghezzi, Laura; Salter, Amber; Dorsett, Yair; Chen, Lei; Phillips, Daniel; Weinstock, George M.; Fontana, Luigi (Jun 5, 2018). "Intermittent Fasting Confers Protection in CNS Autoimmunity by Altering the Gut Microbiota". Cell Metabolism. 27 (6): 1222–1235.e6. doi:10.1016/j.cmet.2018.05.006. ISSN 1932-7420. PMC . PMID 29874567.
- Craig, Courtney (November 2015), "Mitoprotective dietary approaches for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Caloric restriction, fasting, and ketogenic diets", Medical Hypotheses, 85 (5): 690-693, doi:10.1016/j.mehy.2015.08.013, PMID 26315446