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|keywords=Kukshi, capacity of stomach, digestion, quantity of food, diet, poor digestion, ama, visuchika, alasaka, Ayurveda, Indian system of medicine, charak samhita, satiety, factors affecting digestion, non infectious gastroenteritis, sluggish bowel.

|keywords=Kukshi, capacity of stomach, digestion, quantity of food, diet, poor digestion, ama, visuchika, alasaka, Ayurveda, Indian system of medicine, charak samhita, satiety, factors affecting digestion, non infectious gastroenteritis, sluggish bowel.

|description=Vimana Sthana Chapter 2. Three parts of abdomen and principles of diet

|description=Vimana Sthana Chapter 2. Three parts of abdomen and principles of diet

|image=http://www.carakasamhitaonline.com/mediawiki-1.32.1/resources/assets/ogimgs.jpg

|image=http://www.carakasamhitaonline.com/resources/assets/ogimgs.jpg

|image_alt=charak samhita

|image_alt=charak samhita

|type=article

|type=article

Eswaran H. T. et. al. prepared an [[agni]] assessment scale comprising 64 questions to evaluate the four types of [[agni]]. The study has validated a scale for internal consistency. <ref>Eswaran HT, Kavita MB, Tripaty TB, and Shivakumar. Formation and validation of questionnaire to assess Jāṭharāgni. Anc Sci Life.2015 Apr-Jun; 34(4): 203–209.</ref>  Singh A, Patwardhan K. et. al. developed and validated a self-assessment tool to estimate strength of [[agni]] by recording serum lipid parameters. <ref>Singh A, Singh G,  Patwardhan K, Gehlot S. Development, Validation and Verification of a Self-Assessment Tool to Estimate Agnibala (Digestive Strength). J Evid Based Complementary Altern Med. 2017 Jan;22(1):134-140. doi: 10.1177/2156587216656117. Epub 2016 Jul 4.</ref> Patil VC, Baghel MS et. al. developed formulae for assessment of the digestive functions ([[agni]]) during administration of [[snehana]] (internal oleation). <ref>Patil VC, Baghel MS, Thakar AB. Assessment of [[agni]] (digestive process) and [[koshtha]] (bowel movement with special reference to abhyantara [[snehana]] (internal oleation). Ancient Sci. Life. 2008; 28:26-28</ref> These tools are used to assess the status of [[agni]] and determine proper qunatity.  

Eswaran H. T. et. al. prepared an [[agni]] assessment scale comprising 64 questions to evaluate the four types of [[agni]]. The study has validated a scale for internal consistency. <ref>Eswaran HT, Kavita MB, Tripaty TB, and Shivakumar. Formation and validation of questionnaire to assess Jāṭharāgni. Anc Sci Life.2015 Apr-Jun; 34(4): 203–209.</ref>  Singh A, Patwardhan K. et. al. developed and validated a self-assessment tool to estimate strength of [[agni]] by recording serum lipid parameters. <ref>Singh A, Singh G,  Patwardhan K, Gehlot S. Development, Validation and Verification of a Self-Assessment Tool to Estimate Agnibala (Digestive Strength). J Evid Based Complementary Altern Med. 2017 Jan;22(1):134-140. doi: 10.1177/2156587216656117. Epub 2016 Jul 4.</ref> Patil VC, Baghel MS et. al. developed formulae for assessment of the digestive functions ([[agni]]) during administration of [[snehana]] (internal oleation). <ref>Patil VC, Baghel MS, Thakar AB. Assessment of [[agni]] (digestive process) and [[koshtha]] (bowel movement with special reference to abhyantara [[snehana]] (internal oleation). Ancient Sci. Life. 2008; 28:26-28</ref> These tools are used to assess the status of [[agni]] and determine proper qunatity.  

[[Agni]] performs various functions of digestion, metabolism and assimilation. Gastric secretions is a digestive fluid, formed in the stomach and contain numerous compounds including hydrochloric acid (HCL), pepsin, lipase, mucin. Kulatunga et al assessed the status of [[agni]] in the patients of [[pandu]] (anemia and blood deficiency disorders) and find out its relationship with the acidity of gastric secretions by use of fractional test meal examination. Their study concluded that HCL reduction in patients of anemia seriously affects the protein and iron absorption; thus Hypochlorhydria (found in 72.8% of the patients) indicates hypofunction of [[agni]]. <ref>Kulatunga R D H, Rai N P, Ali Z. Status of Agni in Pandu Roga (anemia) and its association with the acidity of gastric secretions-A Clinical Study. IAMJ: Volume 7, Issue 1, January – 2019.</ref> The fractional meal test examination is applied to study status of [[agni]] in relatio to disease formation.  

[[Agni]] performs various functions of digestion, metabolism and assimilation. Gastric secretions are digestive fluid, formed in the stomach and contain numerous compounds including hydrochloric acid (HCL), pepsin, lipase, mucin. Kulatunga et al assessed the status of [[agni]] in the patients of [[pandu]] (anemia and blood deficiency disorders) and found its relationship with the acidity of gastric secretions by use of fractional test meal examination. Their study concluded that HCL reduction in patients of anemia seriously affects the protein and iron absorption; thus Hypochlorhydria (found in 72.8% of the patients) indicates hypofunction of [[agni]]. <ref>Kulatunga R D H, Rai N P, Ali Z. Status of Agni in Pandu Roga (anemia) and its association with the acidity of gastric secretions-A Clinical Study. IAMJ: Volume 7, Issue 1, January – 2019.</ref> The fractional meal test examination is applied to study status of [[agni]] in relation to disease formation.  

=== Varieties of food for determining quantity ===

=== Varieties of food for determining quantity ===

# Suckables(chushya) e.g. sugarcane

# Suckables(chushya) e.g. sugarcane

These food articles are heavy for digestion in ascending order. [B.P. Prathama Khanda 4/142-143] <ref>Bhavamishra. Bhavaprakasha -Volume I. Translated from Sanskrit by K.R. Srikantha Murthy. 1st ed. Varanasi: Krishnadas academy;2000.</ref> These types are further abbreviated under two major classes as liquid foods and solid foods. Both types of food shall be consumed till half of it satiety or till feeling of satiety. If consumed in proper qunatity, these are digested in due time, without disturbing [[dosha]] physiology ([[prakriti]]). Subjective parameters shall be observed carefully to decide the proper quantity of food. [Cha. Sa.[[Vimana Sthana]] 2/6]   

These food articles are heavy to digest in ascending order. [B.P. Prathama Khanda 4/142-143] <ref>Bhavamishra. Bhavaprakasha -Volume I. Translated from Sanskrit by K.R. Srikantha Murthy. 1st ed. Varanasi: Krishnadas academy;2000.</ref> These types are further abbreviated under two major classes as liquid foods and solid foods. Both types of food can be consumed upto half of satiety point. If consumed in proper quantity, these are digested in due time, without disturbing [[dosha]] physiology ([[prakriti]]). Subjective parameters shall be observed carefully to decide the proper quantity of food. [Cha. Sa.[[Vimana Sthana]] 2/6]   

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=== [[Amashaya]]- site of digestion ===

=== [[Amashaya]]- site of digestion ===

Amashaya is a site of digestion of all types of food. After complete digestion, the digested essence of food reaches all the body organs through vessels. Amashaya is a seat of [[pitta dosha]] and [[kapha dosha]] [Cha. Sa.[[Sutra Sthana]] 20/8] and the disorders originated from [[amashaya]] are specifically grouped as the disorders having a predominance of these two [[dosha]]. [Cha.Sa.[[Vimana Sthana]] 6/3] The Pachaka pitta and kledaka kapha play vital role in digestion. [[Amashaya]] is situated between the umbilicus and the breast as per surface anatomy. Stomach is considered as upper segment of [[amashaya]]. Small intestine along with liver and pancreas is considered as the lower segment of [[amashaya]].   

Amashaya is a site of digestion of all types of food. After complete digestion, the digested essence of food reaches all the body organs through vessels. Amashaya is seat of [[pitta dosha]] and [[kapha dosha]] [Cha. Sa.[[Sutra Sthana]] 20/8] and the disorders originated from [[amashaya]] are specifically grouped as the disorders having a predominance of these two [[dosha]]. [Cha.Sa.[[Vimana Sthana]] 6/3] The pachaka pitta and kledaka kapha play vital role in digestion. [[Amashaya]] is situated between the umbilicus and the breast as per surface anatomy. Stomach is considered as upper segment of [[amashaya]]. Small intestine along with liver and pancreas is considered as the lower segment of [[amashaya]].   

=== Proper quantity of food ===

=== Proper quantity of food ===

==== Role of satiety and three parts of ingestion capacity ====

==== Role of satiety and three parts of ingestion capacity ====

Satiety is one of the subjective parameters to assess the ingestion capacity of a person. The maximum ingestion capacity of a person should be divided into three parts. One-third part of food intake should be consumed in solid form and one third part as liquid diet, remaining one third part of total capacity should be kept empty for movement of [[vata]], [[pitta]] and [[kapha]]. This is the indicator of satiety. This means once the two third part of stomach will be filled, a person will have the feeling of satisfaction [Cha.Sa.[[Sutra Sthana]]25/40]. At this point the person should stop eating. If this limit is crossed, the excess food stuff will occupy the third part of stomach which interrupts the process of digestion, causing extra burden on [[agni]] (digestive power) and may result indigestion. The divisions of stomach (amashaya) are not in equal proportion, but it is in accordance with user’s suitability and the adaptive pattern of food consumption [Chakrapani on Cha.Sa.[[Vimana Sthana]]2/3]. Power of ingestion (abhyavaharana shakti) is different for every individual and it depends upon the strength of digestive capacity (jatharagni). The proper quantity of food (ahara matra) to be consumed is subjected to power of ingestion and consistency of food articles i.e. solid and liquid.

Satiety is one of the subjective parameters to assess the ingestion capacity of a person. The maximum ingestion capacity of a person should be divided into three parts. One-third part of food intake should be consumed in solid form and one third part as liquid diet, remaining one third part of total capacity should be kept empty for movement of [[vata]], [[pitta]] and [[kapha]]. This is the indicator of satiety. This means once the two third part of stomach will be filled, a person will have the feeling of satisfaction [Cha.Sa.[[Sutra Sthana]]25/40]. At this point the person should stop eating. If this limit is crossed, the excess food stuff will occupy the third part of stomach which interrupts the process of digestion, causing extra burden on [[agni]] (digestive power) and may cause indigestion. The divisions of stomach ([[amashaya]]) are not in equal proportion, but it is in accordance with user’s suitability and the adaptive pattern of food consumption [Chakrapani on Cha.Sa.[[Vimana Sthana]]2/3]. Power of ingestion (abhyavaharana shakti) is different for every individual and it depends upon the strength of digestive capacity (jatharagni). The proper quantity of food (ahara matra) to be consumed subject to power of ingestion and consistency of food articles i.e. solid and liquid.

Some Ayurveda scholars have divided ingestion capacity of [[amashaya]] in four parts and advised to take two parts with solid food, one part with liquids and rest one fourth part to be left empty for [[dosha]] (as a normal physiology of digestion). [A.Hr.[[Sutra Sthana]]8/46-47]<ref name="A. Hridaya">Vagbhata. Ashtanga Hridayam. Edited by Harishastri Paradkar Vaidya. 1st ed. Varanasi: Krishnadas Academy;2000.</ref> Arundatta, commentator of Vagbhata has considered this capacity of [[amashaya]] as the measurement of satiety.

Some Ayurveda scholars have divided ingestion capacity of [[amashaya]] in four parts and advised to take two parts with solid food, one part with liquids and rest one fourth part to be left empty for [[dosha]] (as a normal physiology of digestion). [A.Hr.[[Sutra Sthana]]8/46-47]<ref name="A. Hridaya">Vagbhata. Ashtanga Hridayam. Edited by Harishastri Paradkar Vaidya. 1st ed. Varanasi: Krishnadas Academy;2000.</ref> Arundatta, commentator of Vagbhata has considered this capacity of [[amashaya]] as the measurement of satiety.

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Satiation is a process that leads to the termination of eating, which may be accompanied by a feeling of satisfaction. Proper quantity of food (sauhitya matra) means eat till the filling of satiety. This satiety term is further differentiated into two functionally different terminologies namely satiation and satiety. Benelam B defines Satiation as the process that leads to termination of eating, accompanied by feeling of satisfaction. This is also called as within meal satiety. Further he defines Satiety as the feeling of fullness that persists after eating, potentially suppressing further energy intake until hunger returns .<ref>Benelam B. Satiation, Satiety and their effects on eating behavior. Nutrition Bulletin. London UK. British Nutrition Foundation. May 2009;34(2):126–173.

Satiation is a process that leads to the termination of eating, which may be accompanied by a feeling of satisfaction. Proper quantity of food (sauhitya matra) means eat till the feeling of satiety. This satiety term is further differentiated into two functionally different terminologies namely satiation and satiety. Benelam B defines Satiation as the process that leads to termination of eating, accompanied by feeling of satisfaction. This is also called as within meal satiety. Further he defines Satiety as the feeling of fullness that persists after eating, potentially suppressing further energy intake until hunger returns .<ref>Benelam B. Satiation, Satiety and their effects on eating behavior. Nutrition Bulletin. London UK. British Nutrition Foundation. May 2009;34(2):126–173.

https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1467-3010.2009.01753.x </ref>Sorensen LB termed it as between-meal satiety. It is the state where eating is inhibited till next eating episode.<ref>Sørensen LB, Møller P, Flint A, Martens M, Raben A. Effect of sensory perception of foods on appetite and food intake: a review of studies on humans. Int J Obes Relat Metab Disord. 2003;27(10):1152-1166. doi:10.1038/sj.ijo.0802391</ref>

https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1467-3010.2009.01753.x </ref>Sorensen LB termed it as between-meal satiety. It is the state where eating is inhibited till next eating episode.<ref>Sørensen LB, Møller P, Flint A, Martens M, Raben A. Effect of sensory perception of foods on appetite and food intake: a review of studies on humans. Int J Obes Relat Metab Disord. 2003;27(10):1152-1166. doi:10.1038/sj.ijo.0802391</ref>

Gut hormones such as cholecystokinin (CCK) and GLP-1, Oxyntomodulin (OXM), Peptide YY, Pancreatic polypeptide (PP) these are the important gut hormones involved in the mechanism of satiation, plays significant role in termination of meal. CCK is considered as potential biomarker for satiation.<ref>Melton PM, Kissileff HR, Pi-Sunyer FX. Cholecystokinin (CCK-8) affects gastric pressure and ratings of hunger and fullness in women. Am J Physiol. 1992;263(2 Pt 2):R452-R456. doi:10.1152/ajpregu.1992.263.2.R452</ref><ref>Shah M, Vella A. Effects of GLP-1 on appetite and weight. Rev Endocr Metab Disord. 2014;15(3):181-187. doi:10.1007/s11154-014-9289-5</ref> Oxyntomodulin (OXM) delays gastric emptying and reduces gastric acid secretion, decrease food intake.<ref>Sam AH, Troke RC, Tan TM, Bewick GA. The role of the gut/brain axis in modulating food intake. Neuropharmacology. 2012;63(1):46-56.doi:10.1016/j.neuropharm.2011.10.008</ref>  

Gut hormones such as cholecystokinin (CCK) and GLP-1, Oxyntomodulin (OXM), Peptide YY, Pancreatic polypeptide (PP) these are the important gut hormones involved in the mechanism of satiation, plays significant role in termination of meal. CCK is considered as potential biomarker for satiation.<ref>Melton PM, Kissileff HR, Pi-Sunyer FX. Cholecystokinin (CCK-8) affects gastric pressure and ratings of hunger and fullness in women. Am J Physiol. 1992;263(2 Pt 2):R452-R456. doi:10.1152/ajpregu.1992.263.2.R452</ref><ref>Shah M, Vella A. Effects of GLP-1 on appetite and weight. Rev Endocr Metab Disord. 2014;15(3):181-187. doi:10.1007/s11154-014-9289-5</ref> Oxyntomodulin (OXM) delays gastric emptying and reduces gastric acid secretion, decrease food intake.<ref>Sam AH, Troke RC, Tan TM, Bewick GA. The role of the gut/brain axis in modulating food intake. Neuropharmacology. 2012;63(1):46-56.doi:10.1016/j.neuropharm.2011.10.008</ref>  

Leptin, insulin, and ghrelin act as long term regulators of appetite. These are long-acting adiposity hormones. While studying the role of leptin in prandial patterns, researchers observed that plasma leptin concentrations increase during a spontaneous intermeal interval and decline before the onset of a meal. Leptin works through regulation of hypothalamic feeding circuits. Through negative feedback mechanism leptin reduces food intake and regulates body weight homeostasis. Thus decreased leptin levels observed to stimulate appetite behavior. Leptin has an influential role in meal frequency and observed less responsible to control meal size.<ref>Chapelot D, Aubert R, Marmonier C, Chabert M, Louis-Sylvestre J. An endocrine and metabolic definition of the intermeal interval in humans: evidence for a role of leptin on the prandial pattern through fatty acid disposal. Am J Clin Nutr. 2000 Aug;72(2):421-31. doi: 10.1093/ajcn/72.2.421. PMID: 10919937.https://academic.oup.com/ajcn/article/72/2/421/4729460</ref>

Leptin, insulin, and ghrelin act as long term regulators of appetite. These are long-acting adiposity hormones. While studying the role of leptin in prandial patterns, researchers observed that plasma leptin concentrations increase during a spontaneous inter-meal interval and decline before the onset of a meal. Leptin works through regulation of hypothalamic feeding circuits. Through negative feedback mechanism leptin reduces food intake and regulates body weight homeostasis. Thus, decreased leptin levels observed to stimulate appetite behavior. Leptin has an influential role in meal frequency and observed less responsible to control meal size.<ref>Chapelot D, Aubert R, Marmonier C, Chabert M, Louis-Sylvestre J. An endocrine and metabolic definition of the inter-meal interval in humans: evidence for a role of leptin on the prandial pattern through fatty acid disposal. Am J Clin Nutr. 2000 Aug;72(2):421-31. doi: 10.1093/ajcn/72.2.421. PMID: 10919937.https://academic.oup.com/ajcn/article/72/2/421/4729460</ref>

Ghrelin potentially enhances appetite. It is the first hormone which shows stimulating effect on food intake.<ref>Wren AM, Seal LJ, Cohen MA, et al. Ghrelin enhances appetite and increases food intake in humans. J Clin Endocrinol Metab. 2001;86(12):5992. doi:10.1210/jcem.86.12.8111</ref><ref>Kalra SP, Bagnasco M, Otukonyong EE, Dube MG, Kalra PS. Rhythmic, reciprocal ghrelin and leptin signaling: new insight in the development of obesity. Regul Pept. 2003;111(1-3):1-11. doi:10.1016/s0167-0115(02)00305-1</ref> Ghrelin secreted mainly from the gastric mucosa, its level are at their peak just before a meal, and decreased slowly when food nutrients are travelled into intestine. It acts on hippocampal neurons involved in spatial learning and memory, thus empty stomach passes signal to brain for asking to engage in appetite behavior, filling of hunger. Ghrelin as orexigenic factor promoted food intake and weight gain. Various cognitive components participate in the initiation of eating and in the selection of food. Schmid DA et al research findings suggest that along with stimulation of appetite, Ghrelin affects cognitive functions. They have noted vivid, plastic visualization of preferred meal by study subjects after administration of ghrelin.<ref>Schmid DA, Held K, Ising M, Uhr M, Weikel JC, & Steiger A (2005). Ghrelin Stimulates Appetite, Imagination of Food, GH, ACTH, and Cortisol, but does not Affect Leptin in Normal Controls. Neuropsychopharmacology, 30(6), 1187–1192. https://doi.org/10.1038/sj.npp.1300670</ref> Peptide YY has a suppressive effect on food intake.<ref>Jones ES, Nunn N, Chambers AP, Østergaard S, Wulff BS, Luckman SM. Modified Peptide YY Molecule Attenuates the Activity of NPY/AgRP Neurons and Reduces Food Intake in Male Mice. Endocrinology. 2019 Nov 1;160(11):2737-2747. doi: 10.1210/en.2019-00100. PMID: 31074796; PMCID: PMC6806261.</ref>PPY rise is observed in post prandial phase and are lowest in fasting state. Peripheral administration of PYY3e36 reduces food intake. PPY have shown effect on intestinal motility, delays gastric emptying.<ref>Asakawa A, Inui A, Yuzuriha H, Ueno N, Katsuura G, Fujimiya M, Fujino MA, Niijima A, Meguid MM, Kasuga M. Characterization of the effects of pancreatic polypeptide in the regulation of energy balance. Gastroenterology. 2003 May;124(5):1325-36. doi: 10.1016/s0016-5085(03)00216-6. PMID: 12730873.</ref>  

Ghrelin potentially enhances appetite. It is the first hormone which shows stimulating effect on food intake.<ref>Wren AM, Seal LJ, Cohen MA, et al. Ghrelin enhances appetite and increases food intake in humans. J Clin Endocrinol Metab. 2001;86(12):5992. doi:10.1210/jcem.86.12.8111</ref><ref>Kalra SP, Bagnasco M, Otukonyong EE, Dube MG, Kalra PS. Rhythmic, reciprocal ghrelin and leptin signaling: new insight in the development of obesity. Regul Pept. 2003;111(1-3):1-11. doi:10.1016/s0167-0115(02)00305-1</ref> Ghrelin secreted mainly from the gastric mucosa, its level are at their peak just before a meal, and decreased slowly when food nutrients have travelled to intestine. It acts on hippocampal neurons involved in spatial learning and memory, thus empty stomach passes signal to brain for asking to engage in appetite behavior, feeling of hunger. Ghrelin as orexigenic factor promoted food intake and weight gain. Various cognitive components participate in the initiation of eating and in the selection of food. Schmid DA et al research findings suggest that along with stimulation of appetite, ghrelin affects cognitive functions. They have noted vivid visualization of preferred meal by study subjects after administration of ghrelin.<ref>Schmid DA, Held K, Ising M, Uhr M, Weikel JC, & Steiger A (2005). Ghrelin Stimulates Appetite, Imagination of Food, GH, ACTH, and Cortisol, but does not Affect Leptin in Normal Controls. Neuropsychopharmacology, 30(6), 1187–1192. https://doi.org/10.1038/sj.npp.1300670</ref> Peptide YY has a suppressive effect on food intake.<ref>Jones ES, Nunn N, Chambers AP, Østergaard S, Wulff BS, Luckman SM. Modified Peptide YY Molecule Attenuates the Activity of NPY/AgRP Neurons and Reduces Food Intake in Male Mice. Endocrinology. 2019 Nov 1;160(11):2737-2747. doi: 10.1210/en.2019-00100. PMID: 31074796; PMCID: PMC6806261.</ref>PPY rise is observed in post prandial phase and are lowest in fasting state. Peripheral administration of PYY3e36 reduces food intake. PPY have shown effect on intestinal motility, delays gastric emptying.<ref>Asakawa A, Inui A, Yuzuriha H, Ueno N, Katsuura G, Fujimiya M, Fujino MA, Niijima A, Meguid MM, Kasuga M. Characterization of the effects of pancreatic polypeptide in the regulation of energy balance. Gastroenterology. 2003 May;124(5):1325-36. doi: 10.1016/s0016-5085(03)00216-6. PMID: 12730873.</ref>  

=====3. Signaling pathways involved in the mechanism of satiation =====

=====3. Signaling pathways involved in the mechanism of satiation =====

Food is considered the basic necessity for sustenance of life and attain physical stoutness [Cha.Sa.[[Sutra Sthana]] 25/40(1)]. Energy hemostasis depends on food we consume. Hypothalamus and brainstem are mainly involved to maintain the energy levels. The arcuate nucleus (ARC) of hypothalamus plays important role to control intake of food. ARC has orexigenic neurons (appetite stimulating) and anorexigenic neurons (appetite inhibiting). During digestion, food nutrients stimulate G-protein coupled receptor present on enteroendocrine cell, which stimulates release of gut hormone. Gut hormones influences the vagus nerve, hypothalamus and brainstem. Stimulating and inhibitory neurons present in hypothalamus interact with peripheral signals which results in alteration of eating drive. Vagal afferents stimulated by the gut hormone and sensitive to the stomach's mechanical stretch further connect with the nucleus of the brainstem. Brainstem passes neural signals to hypothalamus. Numerous hormonal and neural signals influence ARC nucleus, which projects to a number of regions including hypothalamic paraventricular nucleus where some essential energy regulating pathways arise.  

Food is considered the basic necessity for sustenance of life and attain physical stoutness [Cha.Sa.[[Sutra Sthana]] 25/40(1)]. Energy homeostasis depends on food we consume. Hypothalamus and brainstem are mainly involved to maintain the energy levels. The arcuate nucleus (ARC) of hypothalamus plays important role to control intake of food. ARC has orexigenic neurons (appetite stimulating) and anorexigenic neurons (appetite inhibiting). During digestion, food nutrients stimulate G-protein coupled receptor present on enteroendocrine cell, which stimulates release of gut hormone. Gut hormones influences the vagus nerve, hypothalamus and brainstem. Stimulatory and inhibitory neurons present in hypothalamus interact with peripheral signals which results in alteration of eating drive. Vagal afferents stimulated by the gut hormone and sensitive to the stomach's mechanical stretch further connect with the nucleus of the brainstem. Brainstem passes neural signals to hypothalamus. Numerous hormonal and neural signals influence ARC nucleus, which projects to a number of regions including hypothalamic paraventricular nucleus where some essential energy regulating pathways arise.  

Gastrointestinal tract releases various peptide hormones. Stomach has its hormonal and neural control mechanism. Presence of food nutrients along with distention of stomach release gut hormones such as PPY, GLP-1, and oxyntomodulin (OXM).Theses are mainly responsible for phenomenon of satiation. These peptide, decreases hypothalamic orexigenic signaling and increases anorexigenic signaling. Negative feedback mechanism results due to these peptides also contribute to increase satiety between meals. Effect of these gut hormones in union with CNS effect results in satiation and satiety. The enteroendocrine cells released hormones interact at different brain levels through circulation and or through primary afferent neurons. Along with induction of satiation and meal termination, gut hormones also produce a positive feeling of reward and satisfaction. Nutrient sensors and their signaling to brain are vital to give feeling of satisfaction.<ref>Sam AH, Troke RC, Tan TM, Bewick GA. The role of the gut/brain axis in modulating food intake. Neuropharmacology. 2012 Jul;63(1):46-56. doi: 10.1016/j.neuropharm.2011.10.008. Epub 2011 Oct 21. PMID: 22037149</ref> <ref>Murphy KG, Bloom SR. Gut hormones and the regulation of energy homeostasis. Nature. 2006 Dec 14;444(7121):854-9. doi: 10.1038/nature05484. PMID: 17167473.</ref> <ref>Berthoud HR. Vagal and hormonal gut-brain communication: from satiation to satisfaction. Neurogastroenterol Motil. 2008;20 Suppl 1(0 1):64-72. doi:10.1111/j.1365-2982.2008.01104.</ref>

Gastrointestinal tract releases various peptide hormones. Stomach has its hormonal and neural control mechanism. Presence of food nutrients along with distention of stomach release gut hormones such as PPY, GLP-1, and oxyntomodulin (OXM).These are mainly responsible for phenomenon of satiation. These peptides decrease hypothalamic orexigenic signaling and increase anorexigenic signaling. Negative feedback mechanism results due to these peptides also contribute to increase satiety between meals. Effect of these gut hormones in union with CNS effect results in satiation and satiety. The enteroendocrine cells released hormones interact at different brain levels through circulation and or through primary afferent neurons. Along with induction of satiation and meal termination, gut hormones also produce a positive feeling of reward and satisfaction. Nutrient sensors and their signaling to brain are vital to give feeling of satisfaction.<ref>Sam AH, Troke RC, Tan TM, Bewick GA. The role of the gut/brain axis in modulating food intake. Neuropharmacology. 2012 Jul;63(1):46-56. doi: 10.1016/j.neuropharm.2011.10.008. Epub 2011 Oct 21. PMID: 22037149</ref> <ref>Murphy KG, Bloom SR. Gut hormones and the regulation of energy homeostasis. Nature. 2006 Dec 14;444(7121):854-9. doi: 10.1038/nature05484. PMID: 17167473.</ref> <ref>Berthoud HR. Vagal and hormonal gut-brain communication: from satiation to satisfaction. Neurogastroenterol Motil. 2008;20 Suppl 1(0 1):64-72. doi:10.1111/j.1365-2982.2008.01104.</ref>

D Chapelot has described subjective and objective tools for measuring meal size, microstructure of the meal, meal request and inter-meal intervals. A multidimensional approach for assessing satiety is proposed with intensity, duration and intake as main variables.<ref>Chapelot D. Quantifying satiation and satiety. In: Blundell JE, Bellisle F, ed. Satiation, Satiety and the Control of Food Intake:Woodhead Publishing Series in Food Science, Technology and Nutrition; 2013:Pages12-39.  https://www.sciencedirect.com/science/book/9780857095435</ref> Commings DE et.al have reviewed the interaction of gastric, intestinal, and pancreatic signals in food regulation. They have also discussed the important role of short acting GI factors and long-acting adiposity hormones in food intake regulation. Gerry Smith survey indicates that gastric signals are volumetric in nature and intestinal signals are nutritive in nature.<ref>Powley TL, Phillips RJ. Gastric satiation is volumetric, intestinal satiation is nutritive. Physiol Behav. 2004 Aug;82(1):69-74. doi: 10.1016/j.physbeh.2004.04.037. PMID: 15234593.</ref>

D Chapelot has described subjective and objective tools for measuring meal size, microstructure of the meal, meal request and inter-meal intervals. A multidimensional approach for assessing satiety is proposed with intensity, duration and intake as main variables.<ref>Chapelot D. Quantifying satiation and satiety. In: Blundell JE, Bellisle F, ed. Satiation, Satiety and the Control of Food Intake:Woodhead Publishing Series in Food Science, Technology and Nutrition; 2013:Pages12-39.  https://www.sciencedirect.com/science/book/9780857095435</ref> Commings DE et.al have reviewed the interaction of gastric, intestinal, and pancreatic signals in food regulation. They have also discussed the important role of short acting GI factors and long-acting adiposity hormones in food intake regulation. Gerry Smith survey indicates that gastric signals are volumetric in nature and intestinal signals are nutritive in nature.<ref>Powley TL, Phillips RJ. Gastric satiation is volumetric, intestinal satiation is nutritive. Physiol Behav. 2004 Aug;82(1):69-74. doi: 10.1016/j.physbeh.2004.04.037. PMID: 15234593.</ref>

A deficient and excessive quantity of food both are detrimental to human health. The deficient quantity of food reduces strength, complexion, and nourishment of body tissues and makes the person a home for various disorders of [[vata dosha]]. The quantity of food is one of the major factors which decide the wholesome and unwholesome effect of food on body tissues. [Cha.Sa.[[Sutra Sthana]] 25/32]  

A deficient and excessive quantity of food both are detrimental to human health. The deficient quantity of food reduces strength, complexion, and nourishment of body tissues and makes the person a home for various disorders of [[vata dosha]]. The quantity of food is one of the major factors which decide the wholesome and unwholesome effect of food on body tissues. [Cha.Sa.[[Sutra Sthana]] 25/32]  

Under eating or intake of food in reduced quantity (pramitashanam) is mentioned as the principal cause of emaciation (karshaniyanam) [Cha.Sa.[[Sutra Sthana]]25/40]. Fasting or over eating does not kindle digestive fire, as like fire in environment is extinguished if there is no fuel supply or if excessive fuel covers the fire. [Cha.Sa.[[Chikitsa Sthana]] 15/211] Taking wholesome food in appropriate quantity after complete digestion of previously eaten food helps to continue good health for long duration.[Cha.Sa.[[Chikitsa Sthana]] 15/214] It is observed that deficient quantity of food deteriorate the digestive capacity of [[agni]] and in absence of sufficient nutrients leads to malnourishment disorders and poor health status.  

Under eating or intake of food in reduced quantity (pramitashanam) is mentioned as the principal cause of emaciation (karshaniyanam) [Cha.Sa.[[Sutra Sthana]]25/40]. Fasting or over-eating does not kindle digestive fire, as like fire in environment is extinguished if there is no fuel supply or if excessive fuel covers the fire. [Cha.Sa.[[Chikitsa Sthana]] 15/211] Taking wholesome food in appropriate quantity after complete digestion of previously eaten food helps to continue good health for long duration.[Cha.Sa.[[Chikitsa Sthana]] 15/214] It is observed that deficient quantity of food deteriorate the digestive capacity of [[agni]] and in absence of sufficient nutrients leads to malnourishment disorders and poor health status.  

There are two ways to measure the quantity of food:

There are two ways to measure the quantity of food:

# Quantity of each food article in a meal (parigraha).

# Quantity of each food article in a meal (parigraha).

The inclusion of different food articles in a meal is to ascertain all the six rasas (tastes) in the required proportion. The nutritional requirement of everybody tissue is different. Proportionate quantity of six [[rasa]] will ensure the tissue requirement.[Fig.3] The balanced diet concept of [[Ayurveda]] is essentially based of this principle. Imbalanced diet concerning six [[rasa]] leads to improper nourishment of body tissues, which further leads to depletion of body tissues ([[dhatu]]) [Chakrapani on Cha. Sa.[[Sutra Sthana]] 5/4]. Long-term exposure of imbalanced diet triggers wear and tear mechanism of tissues and may result in early senility. Biomedical fundamentals of nutrition, macronutrients and micronutrients need to be studied in correlation with Six Rasa principle to offer better nutritional solutions to the society.

The inclusion of different food articles in a meal is to ascertain all the six [[rasa]] (tastes) in the required proportion. The nutritional requirement of various body tissues is different. Proportionate quantity of six [[rasa]] will ensure the tissue requirement.[Fig.3] The balanced diet concept of [[Ayurveda]] is essentially based on this principle. Imbalanced diet concerning six [[rasa]] leads to improper nourishment of body tissues, which further leads to depletion of body tissues ([[dhatu]]) [Chakrapani on Cha. Sa.[[Sutra Sthana]] 5/4]. Long-term exposure of imbalanced diet triggers wear and tear mechanism of tissues and may result in early senility. Biomedical fundamentals of nutrition, macronutrients and micronutrients need to be studied in correlation with six [[rasa]] principle to offer better nutritional solutions to the society.

[[File:VM_Pic.PNG|400px|'''Fig.3: Deficiency of food'''|thumb]]

[[File:VM_Pic.PNG|400px|'''Fig.3: Deficiency of food'''|thumb]]

World health organization explains the malnutrition phenomenon of childhood age under four categories: Stunting, Wasting and overweight and underweight.<ref>United Nations Children’s Fund, World Health Organization, World Bank Group. Levels and trends in child malnutrition: Key findings of the 2012 Edition of the Joint Child Malnutrition Estimates. United Nations Children’s Fund; 2012. www.who.int/nutgrowthdb/estimates</ref> <ref>United Nations Children’s Fund, World Health Organization, World Bank Group. Levels and trends in child malnutrition: Key findings of the 2018 Edition of the Joint Child Malnutrition Estimates. United Nations Children’s Fund; 2018. www.who.int/nutgrowthdb/estimates</ref>

World health organization explains the malnutrition phenomenon of childhood age under four categories: Stunting, Wasting and overweight and underweight.<ref>United Nations Children’s Fund, World Health Organization, World Bank Group. Levels and trends in child malnutrition: Key findings of the 2012 Edition of the Joint Child Malnutrition Estimates. United Nations Children’s Fund; 2012. www.who.int/nutgrowthdb/estimates</ref> <ref>United Nations Children’s Fund, World Health Organization, World Bank Group. Levels and trends in child malnutrition: Key findings of the 2018 Edition of the Joint Child Malnutrition Estimates. United Nations Children’s Fund; 2018. www.who.int/nutgrowthdb/estimates</ref>

    

    

'''1.Stunting''' (height-for-age below –2 SD) refers to a child who is too short for his or her age. It is the devastating result of poor nutrition during early childhood. These children fell to attain complete possible height. It also hampers cognitive development.

'''1.Stunting''' (height-for-age below –2 SD) refers to a child who is too short for his or her age. It is the devastating result of poor nutrition during early childhood. These children fail to attain complete possible height. It also hampers cognitive development.

'''2.Wasting''' (weight-for-height below –2SD) refers to a too thin child for his or her height. It results due to poor nutrient intake. Children suffering from wasting have weakened immunity, suffers long term developmental delay.

'''2.Wasting''' (weight-for-height below –2SD) refers to a too thin child for his or her height. It results due to poor nutrient intake. Children suffering from wasting have weakened immunity, suffer long term developmental delay.

'''3.Childhood overweight''' (weight-for-height above +2SD )and obesity are considered an emerging face of malnutrition, resulting in unhealthy, processed food. In later life this increases the risk for diet related non communicable diseases.

'''3.Childhood overweight''' (weight-for-height above +2SD )and obesity are considered an emerging face of malnutrition, resulting in unhealthy, processed food. In later life this increases the risk for diet related non communicable diseases.

Faustin Habyarimana found key determinants of malnutrition of children below five years of age: age, gender, birth weights, mother’s knowledge of nutrition, birth order, incidence of recent fever, multiple pregnancies, education level of the mother, age of the mother at childbirth, body mass index, prevalence of anemia, province, source of drinking water and wealth quintiles. A positive correlation between stunting and underweight and wasting and underweight was also found.<ref>F. Habyarimana , T. Zewotir , S. Ramroop. Key determinants of malnutrition of children under five years of age in Rwanda: Simultaneous measurement of three anthropometric indices. African Population Studies. Vol. 30, No. 2, 2016</ref>

Faustin Habyarimana found key determinants of malnutrition of children below five years of age: age, gender, birth weights, mother’s knowledge of nutrition, birth order, incidence of recent fever, multiple pregnancies, education level of the mother, age of the mother at childbirth, body mass index, prevalence of anemia, province, source of drinking water and wealth quintiles. A positive correlation between stunting and underweight and wasting and underweight was also found.<ref>F. Habyarimana , T. Zewotir , S. Ramroop. Key determinants of malnutrition of children under five years of age in Rwanda: Simultaneous measurement of three anthropometric indices. African Population Studies. Vol. 30, No. 2, 2016</ref>

'''Consequences of under-nutrition:'''  The consequences of poor nutrition include impaired growth, poor cognitive and social development, poor school performance, increased risk of morbidity and mortality and reduced productivity later in life.<ref>Boah M, Azupogo F, Amporfro DA, Abada LA. The epidemiology of undernutrition and its determinants in children under five years in Ghana. PLoS One. 2019 Jul 31;14(7):e0219665. doi: 10.1371/journal.pone.0219665. PMID: 31365528; PMCID: PMC6668784.</ref> Malnutrition in children’s by impacting cognitive functions, further impend individuals’ ability to lead productive lives and thus contribute to poverty.

'''Consequences of under-nutrition:'''  The consequences of poor nutrition include impaired growth, poor cognitive and social development, poor school performance, increased risk of morbidity and mortality and reduced productivity later in life.<ref>Boah M, Azupogo F, Amporfro DA, Abada LA. The epidemiology of undernutrition and its determinants in children under five years in Ghana. PLoS One. 2019 Jul 31;14(7):e0219665. doi: 10.1371/journal.pone.0219665. PMID: 31365528; PMCID: PMC6668784.</ref> Malnutrition in children affects by impacting cognitive functions, further impends individuals’ ability to lead productive life and thus contribute to poverty.

'''Under-nutrition in adults:'''  Under-nutrition in adults can be correlated with the etiopathogenesis of Karshya described in Ayurveda classics.  Undernourishment may be caused by the lack of one or more nutrients (under‐nutrition), or an excess of nutrients (over‐nutrition). Physiological changes associated with the process of ageing may further support malnutrition.<ref>Guyonnet S, Rolland Y. Screening for Malnutrition in Older People. Clin Geriatr Med. 2015 Aug;31(3):429-37. doi: 10.1016/j.cger.2015.04.009. Epub 2015 May 13. PMID: 26195101.</ref> <ref>Elia M. Defining, Recognizing, and Reporting Malnutrition. Int J Low Extrem Wounds. 2017 Dec;16(4):230-237. doi: 10.1177/1534734617733902. Epub 2017 Nov 16. PMID: 29145755.</ref>

'''Under-nutrition in adults:'''  Under-nutrition in adults can be correlated with the etiopathogenesis of [[Karshya]] described in Ayurveda classics.  Undernourishment may be caused by the lack of one or more nutrients (under‐nutrition), or an excess of nutrients (over‐nutrition). Physiological changes associated with the process of ageing may further support malnutrition.<ref>Guyonnet S, Rolland Y. Screening for Malnutrition in Older People. Clin Geriatr Med. 2015 Aug;31(3):429-37. doi: 10.1016/j.cger.2015.04.009. Epub 2015 May 13. PMID: 26195101.</ref> <ref>Elia M. Defining, Recognizing, and Reporting Malnutrition. Int J Low Extrem Wounds. 2017 Dec;16(4):230-237. doi: 10.1177/1534734617733902. Epub 2017 Nov 16. PMID: 29145755.</ref>

'''Determinants''': Hickson M has Categorized the causes of malnutrition under three category as medical factors (like poor appetite, physical disability, endocrine disorders etc), lifestyle and social factors (lack of knowledge of nutrition, loneliness, povery etc.) and psychological factors.<ref>Hickson M. Malnutrition and ageing. Postgrad Med J. 2006;82(963):2-8. doi: 10.1136/ pgmj .2005.037564</ref>   

'''Determinants''': Hickson M has Categorized the causes of malnutrition under three category as medical factors (like poor appetite, physical disability, endocrine disorders etc), lifestyle and social factors (lack of knowledge of nutrition, loneliness, povery etc.) and psychological factors.<ref>Hickson M. Malnutrition and ageing. Postgrad Med J. 2006;82(963):2-8. doi: 10.1136/ pgmj .2005.037564</ref>   

Morley JE has enumerated the major causes of malnutrition as lack of food, paranoia, emotional factors (like depression), inappropriate dieting, anorexia, problem with feeding (tremors, dementia, functional impairment, and dysphagia), Enteral problems (e.g., gluten enteropathy), Wandering and other dementia related factors and malabsorption.<ref>Morley JE. Editorial: Defining Undernutrition (Malnutrition) in Older Persons. J Nutr Health Aging. 2018;22(3):308-310. doi: 10.1007/s12603-017-0991-3. PMID: 29484342.</ref>

Morley JE has enumerated the major causes of malnutrition as lack of food, paranoia, emotional factors (like depression), inappropriate dieting, anorexia, problem with feeding (tremors, dementia, functional impairment, and dysphagia), Enteral problems (e.g., gluten enteropathy), Wandering and other dementia related factors and malabsorption.<ref>Morley JE. Editorial: Defining Undernutrition (Malnutrition) in Older Persons. J Nutr Health Aging. 2018;22(3):308-310. doi: 10.1007/s12603-017-0991-3. PMID: 29484342.</ref>

Old age persons are at high risk of developing protein-energy malnutrition. It affects health, cognitive and physical functions as well as quality of life. Study concludes that increasing age, unmarried/separated/divorced status, difficulties walking 100 m, climbing stairs and hospitalization, cognitive impairment or receiving social support are the major predictors of malnutrition.<ref>Corish CA, Bardon LA. Malnutrition in older adults: screening and determinants. Proc Nutr Soc. 2019 Aug;78(3):372-379. doi: 10.1017/S0029665118002628. Epub 2018 Dec 3. PMID: 30501651.</ref>

Older people are at high risk of developing protein-energy malnutrition. It affects health, cognitive and physical functions as well as quality of life. Study concludes that increasing age, unmarried/separated/divorced status, difficulties walking 100 m, climbing stairs and hospitalization, cognitive impairment or receiving social support are the major predictors of malnutrition.<ref>Corish CA, Bardon LA. Malnutrition in older adults: screening and determinants. Proc Nutr Soc. 2019 Aug;78(3):372-379. doi: 10.1017/S0029665118002628. Epub 2018 Dec 3. PMID: 30501651.</ref>

Shetty P has validated scoring systems such as MUST, which indicates patients at risk of malnutrition. BMI less than 18.5 kg/m2 is a sign of undernutrition. Laboratory investigations like hemoglobin or packed cell volume (indicators of anemia, hydration), blood urea (indicating hydration and  protein intake), C-reactive protein and ESR (inflammatory pathology), total lymphocyte count (for immune function) are also suggested to aid early diagnosis.<ref>Shetty, P. (2006). Malnutrition and undernutrition. Medicine, 34(12), 524–529. https://doi.org/10.1053/j.mpmed.2006.09.014</ref>Donini LM et al developed and validated a screening tool for the easy detection and reporting of both undernutrition and over-nutrition, two types of malnutrition.<ref>Donini LM, Ricciardi, L. M., Neri, B., Lenzi, A., & Marchesini, G. (2014). Risk of malnutrition (over and under-nutrition): Validation of the JaNuS screening tool. Clinical Nutrition, 33(6), 1087–1094. https://doi.org/10.1016/j.clnu.2013.12.001</ref> A systematic review to evaluate malnutrition biomarkers among older adults, concluded that BMI, hemoglobin, and total cholesterol are useful biomarkers of malnutrition in older adults.<ref>Zhang Z, Pereira SL, Luo M, Matheson EM. Evaluation of blood biomarkers associated with risk of malnutrition in older adults: A Systematic Review and Meta-Analysis. Nutrients. 2017 Aug 3;9(8):829. doi: 10.3390/nu9080829. PMID: 28771192; PMCID: PMC5579622</ref>

Shetty P has validated scoring systems such as MUST, which indicates patients at risk of malnutrition. BMI less than 18.5 kg/m2 is a sign of undernutrition. Laboratory investigations like hemoglobin or packed cell volume (indicators of anemia, hydration), blood urea (indicating hydration and  protein intake), C-reactive protein and ESR (inflammatory pathology), total lymphocyte count (for immune function) are also suggested to aid early diagnosis.<ref>Shetty, P. (2006). Malnutrition and undernutrition. Medicine, 34(12), 524–529. https://doi.org/10.1053/j.mpmed.2006.09.014</ref>Donini LM et al developed and validated a screening tool for the easy detection and reporting of both undernutrition and over-nutrition, two types of malnutrition.<ref>Donini LM, Ricciardi, L. M., Neri, B., Lenzi, A., & Marchesini, G. (2014). Risk of malnutrition (over and under-nutrition): Validation of the JaNuS screening tool. Clinical Nutrition, 33(6), 1087–1094. https://doi.org/10.1016/j.clnu.2013.12.001</ref> A systematic review to evaluate malnutrition biomarkers among older adults, concluded that BMI, hemoglobin, and total cholesterol are useful biomarkers of malnutrition in older adults.<ref>Zhang Z, Pereira SL, Luo M, Matheson EM. Evaluation of blood biomarkers associated with risk of malnutrition in older adults: A Systematic Review and Meta-Analysis. Nutrients. 2017 Aug 3;9(8):829. doi: 10.3390/nu9080829. PMID: 28771192; PMCID: PMC5579622</ref>

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Excessive food triggers all three [[dosha]] vitiation as there is no space left for functions of [[dosha]]. [[Dosha]] govern the physiology of digestion. Samana [[vayu]] functions nearby the abode of digestive factors (jatharagni), kindles [[agni]]. Prana [[vayu]] and apana [[vayu]] supports the functions of [[agni]]. Pachaka [[pitta]] when devoid of its liquid property, is responsible for digestion.[A. Hr. Sutra Sthana 12/10-11]<ref name="A. Hridaya"/> Kledaka [[kapha]] is responsible to moisten the ingested food. Thus the process of digestion is driven by [[dosha]]. Factors responsible for complete transformation and absorption of food(ahara parinamakara bhava) explain this phenomenon in-depth. [Cha.Sa.[[Sharira Sthana]]6/14],[Cha.Sa.[[Chikitsa Sthana]] 15/6-8]. The normal functions of digestion and metabolism are not carried out due to the vitiated [[dosha]]. This leads to the formation of [[ama]].  

Excessive food triggers all three [[dosha]] vitiation as there is no space left for functions of [[dosha]]. [[Dosha]] govern the physiology of digestion. Samana [[vayu]] functions nearby the abode of digestive factors (jatharagni), kindles [[agni]]. Prana [[vayu]] and apana [[vayu]] supports the functions of [[agni]]. Pachaka [[pitta]] when devoid of its liquid property, is responsible for digestion. [A. Hr. Sutra Sthana 12/10-11]<ref name="A. Hridaya"/> Kledaka [[kapha]] is responsible to moisten the ingested food. Thus the process of digestion is driven by [[dosha]]. Factors responsible for complete transformation and absorption of food (ahara parinamakara bhava) explain this phenomenon in-depth. [Cha.Sa.[[Sharira Sthana]]6/14],[Cha.Sa.[[Chikitsa Sthana]] 15/6-8]. The normal functions of digestion and metabolism are not carried out due to the vitiated [[dosha]]. This leads to the formation of [[ama]].  

Excessive eating is one of the etiological factors for non-communicable diseases like obesity and diabetes mellitus which are more prevalent in society. Excess intake of calorie food which is not processed properly by digestive power (jatharagni) and further utilized by dhatvagni (type of [[agni]] present at tissue level) leads to obesity and related disorders.

Excessive eating is one of the etiological factors for non-communicable diseases like obesity and diabetes mellitus which are more prevalent in society. Excess intake of calorie food which is not processed properly by digestive power (jatharagni) and further utilized by dhatvagni (type of [[agni]] present at tissue level) leads to obesity and related disorders.

Gut microbiome plays a significant role in intestinal physiology and regulation. Gut microbiota produces microbial metabolites like short-chain fatty acids (SCFAs) mainly acetate, propionate, and butyrate; promotes local intestinal immunizations and systemic immunity  .<ref>Yoon MY, Lee K, Yoon SS. Erratum to: Protective role of gut commensal microbes against intestinal infections. J Microbiol. 2015 Jan;53(1):90. doi: 10.1007/s12275-015-0705-7. Erratum for: J Microbiol. 2014 Dec;52(12):983-9. Yoon, My Young [corrected to Yoon, Mi Young]. PMID: 25557484. </ref> <ref>Zhang H, Sparks JB, Karyala SV, Settlage R, Luo XM. Host adaptive immunity alters gut microbiota. ISME J. 2015 Mar;9(3):770-81. doi: 10.1038/ismej.2014.165. Epub 2014 Sep 12. PMID: 25216087; PMCID: PMC4331585.</ref>Gut microbiome has a regulatory role in behavior and cognition and it is exercised through gut-brain axis.<ref>Mohajeri MH, Brummer RJM, Rastall RA, Weersma RK, Harmsen HJM, Faas M, Eggersdorfer M. The role of the microbiome for human health: from basic science to clinical applications. Eur J Nutr. 2018 May;57(Suppl 1):1-14. doi: 10.1007/s00394-018-1703-4. PMID: 29748817; PMCID:PMC5962619.https://link.springer.com/article/10.1007/s00394-018-1703-4</ref>

Gut microbiome plays a significant role in intestinal physiology and regulation. Gut microbiota produces microbial metabolites like short-chain fatty acids (SCFAs) mainly acetate, propionate, and butyrate; promotes local intestinal immunizations and systemic immunity  .<ref>Yoon MY, Lee K, Yoon SS. Erratum to: Protective role of gut commensal microbes against intestinal infections. J Microbiol. 2015 Jan;53(1):90. doi: 10.1007/s12275-015-0705-7. Erratum for: J Microbiol. 2014 Dec;52(12):983-9. Yoon, My Young [corrected to Yoon, Mi Young]. PMID: 25557484. </ref> <ref>Zhang H, Sparks JB, Karyala SV, Settlage R, Luo XM. Host adaptive immunity alters gut microbiota. ISME J. 2015 Mar;9(3):770-81. doi: 10.1038/ismej.2014.165. Epub 2014 Sep 12. PMID: 25216087; PMCID: PMC4331585.</ref>Gut microbiome has a regulatory role in behavior and cognition and it is exercised through gut-brain axis.<ref>Mohajeri MH, Brummer RJM, Rastall RA, Weersma RK, Harmsen HJM, Faas M, Eggersdorfer M. The role of the microbiome for human health: from basic science to clinical applications. Eur J Nutr. 2018 May;57(Suppl 1):1-14. doi: 10.1007/s00394-018-1703-4. PMID: 29748817; PMCID:PMC5962619.https://link.springer.com/article/10.1007/s00394-018-1703-4</ref>

Gut-Brain axis has bidirectional communication between central and enteric nervous system. It connects emotional and cognitive centers of brain to peripheral intestinal functions. By means of neural, endocrine, immune, and humoral links gut microbiota interact with GBA axis .<ref>Moloney RD, Desbonnet L, Clarke G, Dinan TG, Cryan JF. The microbiome: stress, health and disease. Mamm Genome. 2014 Feb; 25(1-2):49-74. doi: 10.1007/s00335-013-9488-5. Epub 2013 Nov 27.</ref>Marilia Carabotti et al in there review article have explored these interactions, as well as the possible pathophysiological mechanisms involved. Microbiota-gut-brain axis monitors and integrates gut functions and links emotional and cognitive centers of the brain with peripheral intestinal functions. This complex network includes central nervous system (CNS), the autonomic nervous system (ANS), the enteric nervous system (ENS) and the hypothalamic pituitary adrenal (HPA) axis. Central nervous system communicates with enteric nervous system (ENS), intestinal muscle layers and gut mucosa through various afferent and efferent autonomic pathways. Gastrointestinal wall connect with CNS through enteric, spinal and vagal efferent pathways. Limbic system which includes Amygdala (AMG), hippocampus (HIPP), and hypothalamus (HYP): predominantly responsible for memory and emotional responses. Hypothalamic pituitary adrenal (HPA) axis which is a part of limbic system activates in response to emotional stress and releases corticotropin-releasing factor (CRF) from the hypothalamus. CRF further stimulates adrenocorticotropic hormone (ACTH) secretion from the pituitary gland, causing the secretion of cortisol (main Stress hormone) from the adrenal glands. This hormone affects brain functions. Brain through neural communication influences various intestinal cell targets. The Gut microbiota also influences these same cells.  Gut microbiota interact locally with intestinal cells and enteric nervous system (ENS), it also connect with central nervous system (CNS) through neuroendocrine and metabolic pathways.<ref>Carabotti M, Scirocco A, Maselli MA, Severi C. The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems. Ann Gastroenterol. 2015 Apr-Jun;28(2):203-209. PMID: 25830558; PMCID:PMC4367209.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4367209/#:~:text=The%20gut%2Dbrain%20axis%20(GBA,microbiota%20in%20influencing%20these%20interactions.</ref>

Gut-Brain axis has bidirectional communication between central and enteric nervous system. It connects emotional and cognitive centers of brain to peripheral intestinal functions. By means of neural, endocrine, immune, and humoral links gut microbiota interact with GBA axis .<ref>Moloney RD, Desbonnet L, Clarke G, Dinan TG, Cryan JF. The microbiome: stress, health and disease. Mamm Genome. 2014 Feb; 25(1-2):49-74. doi: 10.1007/s00335-013-9488-5. Epub 2013 Nov 27.</ref>Marilia Carabotti et al in there review article have explored these interactions, as well as the possible pathophysiological mechanisms involved. Microbiota-gut-brain axis monitors and integrates gut functions and links emotional and cognitive centers of the brain with peripheral intestinal functions. This complex network includes central nervous system (CNS), the autonomic nervous system (ANS), the enteric nervous system (ENS) and the hypothalamic pituitary adrenal (HPA) axis. Central nervous system communicates with enteric nervous system (ENS), intestinal muscle layers and gut mucosa through various afferent and efferent autonomic pathways. Gastrointestinal wall connects with CNS through enteric, spinal and vagal efferent pathways. Limbic system which includes Amygdala (AMG), hippocampus (HIPP), and hypothalamus (HYP): predominantly responsible for memory and emotional responses. Hypothalamic pituitary adrenal (HPA) axis which is a part of limbic system activates in response to emotional stress and releases corticotropin-releasing factor (CRF) from the hypothalamus. CRF further stimulates adrenocorticotropic hormone (ACTH) secretion from the pituitary gland, causing the secretion of cortisol (main Stress hormone) from the adrenal glands. This hormone affects brain functions. Brain through neural communication influences various intestinal cell targets. The Gut microbiota also influences these same cells.  Gut microbiota interact locally with intestinal cells and enteric nervous system (ENS), it also connect with central nervous system (CNS) through neuroendocrine and metabolic pathways.<ref>Carabotti M, Scirocco A, Maselli MA, Severi C. The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems. Ann Gastroenterol. 2015 Apr-Jun;28(2):203-209. PMID: 25830558; PMCID:PMC4367209.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4367209/#:~:text=The%20gut%2Dbrain%20axis%20(GBA,microbiota%20in%20influencing%20these%20interactions.</ref>

Clair R. Martin et al states that Gut microbes communicate to the central nervous system through at least 3 parallel and interacting channels involving nervous, endocrine, and immune signaling mechanisms. Based on preclinical and clinical evidence from various studies, scholars have concluded that  brain by affecting community structure and functions of gut microbiota can modulate regional gut motility, intestinal transit and secretion, and gut permeability, and potentially through the luminal secretion of hormones that directly modulate microbial gene expression.<ref>Martin CR, Osadchiy V, Kalani A, Mayer EA. The Brain-Gut-Microbiome Axis. Cell Mol Gastroenterol Hepatol. 2018 Apr 12;6(2):133-148. doi: 10.1016/j.jcmgh.2018.04.003. PMID: 30023410; PMCID: PMC6047317.</ref>

Clair R. Martin et al states that Gut microbes communicate to the central nervous system through at least 3 parallel and interacting channels involving nervous, endocrine, and immune signaling mechanisms. Based on preclinical and clinical evidence from various studies, scholars have concluded that  brain by affecting community structure and functions of gut microbiota can modulate regional gut motility, intestinal transit and secretion, and gut permeability, and potentially through the luminal secretion of hormones that directly modulate microbial gene expression.<ref>Martin CR, Osadchiy V, Kalani A, Mayer EA. The Brain-Gut-Microbiome Axis. Cell Mol Gastroenterol Hepatol. 2018 Apr 12;6(2):133-148. doi: 10.1016/j.jcmgh.2018.04.003. PMID: 30023410; PMCID: PMC6047317.</ref>

==== Causes of [[ama]] formation ====

==== Causes of [[ama]] formation ====

[[Ama]] is unique concept of [[Ayurveda]]. It is the undigested and non-metabolized food material which remains inside the body and produces toxic effects. This chapter provides details regarding causative factors of [[ama]] formation.Improper quantity of food is considered as an important causative factor in formation of [[ama]]. Furthermore, if [[dietary guidelines]] are not followed, it leads to [[ama]] formation.  

[[Ama]] is unique concept of [[Ayurveda]]. It is the undigested and non-metabolized food material which remains inside the body and produces toxic effects. This section provides details regarding causative factors of [[ama]] formation. Improper quantity of food is considered as an important causative factor in formation of [[ama]]. Furthermore, if [[dietary guidelines]] are not followed, it leads to [[ama]] formation.  

Quality of food like heavy to digest and food with properties like dry, cold, dehydrated, disliked by the consumer, constipation-causing, causing a burning sensation, unclean, incompatible, and/or consumed untimely leads to [[ama]] formation.  

Quality of food like heavy to digest and food with properties like dry, cold, dehydrated, disliked by the consumer, constipation-causing, causing a burning sensation, unclean, incompatible, and/or consumed untimely leads to [[ama]] formation.  

Taking food either in excess quantity or very little quantity is a type of "vishamashana" (a type of unhealthy dietary pattern). This leads to various [[ama]] disorders. [Cha.Sa.[[Chikitsa Sthana]] 15/236]

Taking food either in excess quantity or very little quantity is a type of "vishamashana" (a type of unhealthy dietary pattern). This leads to various [[ama]] disorders. [Cha.Sa.[[Chikitsa Sthana]] 15/236]

Mental factors like food intake while the mind being afflicted with passion/desires, anger, greed, infatuation, envy, bashfulness, grief, conceit, excitement, and fear are also the cause of formation of [[ama]]. Any unwholesome food, even if taken in right quantity also leads to [[ama]] formation. An individual who regularly consumes an incompatible diet, multiple heavy meals (in short intervals) and eats even before the previous meal is digested, results in a clinical state of indigestion characterized by the manifestation of toxic symptoms termed as "ama visha". Some scholars opine that [[ama]] originate from highly vitiated [[dosha]] itself by their conjugation; as visha (aflatoxins) develops in (stored up, edible) kodo millet (kodrava). [A.Hr. Sutra Sthana 13/26]<ref name="A. Hridaya"/> In recent years many non-communicable and metabolic disorders like obesity, diabetes, and thyroid dysfunction are prevalent in society due to indulgence of above factors leading to [[ama]] formation which triggers enormous pathological conditions. Various causal factors should be avoided by an individual to maintain the status [[agni]] and preserve health.  

Mental factors like food intake while the mind being afflicted with passion/desires, anger, greed, infatuation, envy, bashfulness, grief, conceit, excitement, and fear are also the cause of formation of [[ama]]. Any unwholesome food, even if taken in right quantity also leads to [[ama]] formation. An individual who regularly consumes an incompatible diet, multiple heavy meals (in short intervals) and eats even before the previous meal is digested, results in a clinical state of indigestion characterized by the manifestation of toxic symptoms termed as "ama visha". Some scholars opine that [[ama]] originates from highly vitiated [[dosha]] itself by their conjugation; as visha (aflatoxins) develops in (stored up, edible) kodo millet (kodrava). [A.Hr. Sutra Sthana 13/26]<ref name="A. Hridaya"/> In recent years many non-communicable and metabolic disorders like obesity, diabetes, and thyroid dysfunction are prevalent in society due to indulgence of above factors leading to [[ama]] formation which triggers enormous pathological conditions. Various causal factors should be avoided by an individual to maintain the status of [[agni]] to preserve health.  

==== Nature of [[ama]] ====

==== Nature of [[ama]] ====

Due to various etiological factors, deteriorated state of [[agni]] is unable to digest even the light food. [Cha.Sa.[[Chikitsa Sthana]] 15/43]. This afflicted [[agni]] forms an intermediate substance called [[ama]], which turns sour (shukta) during fermentation and finally turns in poisonous substance. (ama visha) [Cha.Sa.[[Chikitsa Sthana]] 15/44]  

Due to various etiological factors, deteriorated state of [[agni]] is unable to digest even the light food. [Cha.Sa.[[Chikitsa Sthana]] 15/43]. This afflicted [[agni]] forms an intermediate substance called [[ama]], which turns sour (shukta) during fermentation and finally turns in poisonous substance. (ama visha) [Cha.Sa.[[Chikitsa Sthana]] 15/44]  

The characteristic features of ama include heavyness, liquid, different colored, unctuous, slimy, sticky, undigested, have fetid smell, continuous pain and considered as root cause of many diseases [Arundatta on A.Hr.Sutra Sthana 13/27].<ref name="A. Hridaya"/> This form of food will not be absorbed, gets associated with [[dosha]] leading to "saama dosha" (undigested food with vitiated [[dosha]]) condition.  

The characteristic features of ama include heaviness, liquid state, various colors, unctuous, slimy, sticky, undigested, have fetid smell and causes continuous pain. It is considered as root cause of many diseases [Arundatta on A.Hr.Sutra Sthana 13/27].<ref name="A. Hridaya"/> This form of food will not be absorbed, gets associated with [[dosha]] leading to "saama dosha" (undigested food with vitiated [[dosha]]) condition.  

==== Symptoms produced due to [[ama]] ====

==== Symptoms produced due to [[ama]] ====

==== Disorders of [[ama]] ====

==== Disorders of [[ama]] ====

Two types of disordres are caused by [[ama]] viz. [[visuchika]] (non infectious gastroenteritis) and [[alasaka]] (sluggish bowels). [[Visuchika]] is characterized by suddent vomiting, diarhoea and pricking pain in abdomen. A frail person having weak digestive power and aggravated [[kapha]] condition, even exerting pressure is not able to elimiate the undigested food out of the passage. This condition is called [[alasaka]].  

Two types of disorders are caused by [[ama]] viz. [[visuchika]] (non infectious gastroenteritis) and [[alasaka]] (sluggish bowels). [[Visuchika]] is characterized by sudden vomiting, diarrhea and pricking pain in abdomen. A frail person having weak digestive power and aggravated [[kapha]] condition, even exerting pressure is not able to eliminate the undigested food out of the passage. This condition is called [[alasaka]].  

==== Assessment of [[ama]] ====

==== Assessment of [[ama]] ====

==== Anal suppositories ====

==== Anal suppositories ====

After emesis, anal suppository play significant role to expel the feces and flatus and to restore the downward movement of apana vayu. [[Swedana]] (sudation therapy) is effective to remove obstruction and to pacify [[vata dosha]].

After emesis, anal suppository plays significant role to expel the feces and flatus and to restore the downward movement of apana vayu. [[Swedana]] (sudation therapy) is effective to remove obstruction and to pacify [[vata dosha]].

==== Stimulation of digestion ====

==== Stimulation of digestion ====

*Natural feeling of hunger and thirst (kshut pipaasa)  

*Natural feeling of hunger and thirst (kshut pipaasa)  

This assessment is essential to know while treating indigestion.[A.S.Sutra Sthana 11/58]

This assessment is essential to know while treating indigestion. [A.S.Sutra Sthana 11/58]

==== Prevention of [[ama]] formation ====

==== Prevention of [[ama]] formation ====

==== [[Ama]] formation at micro channels and cellular level ====

==== [[Ama]] formation at micro channels and cellular level ====

Formation of [[ama]] occurs at the level of tissues or cellular level due to impaired metabolism or due to free radical activity. Free radicals are highly reactive atom or molecule which is having one or more unpaired electrons. It always tries to have stability by giving its electron or by acquiring extra electron form adjacent molecules. After providing the electron adjacent molecule becomes unstable and acts as a free radical, a chain reaction sets in to damage many molecules. A higher concentration of free radicals causes damage to the cellular structure like DNA, protein, lipid, and other cell parts. It causes disturbance in homeostasis of body leading to disease condition.<ref>Sharma GN, Gupta G, Sharma P. A Comprehensive Review of Free Radicals, Antioxidants, and Their Relationship with Human Ailments. Crit Rev Eukaryot Gene Expr. 2018;28(2):139-154. doi:10.1615/CritRevEukaryotGeneExpr.2018022258</ref>

Formation of [[ama]] occurs at the level of tissues or cellular level due to impaired metabolism or due to free radical activity. Free radicals are highly reactive atoms or molecules which have one or more unpaired electrons. It always tries to have stability by giving its electron or by acquiring extra electron form adjacent molecules. After providing the electron adjacent molecule becomes unstable and acts as a free radical, a chain reaction sets in to damage many molecules. A higher concentration of free radicals causes damage to the cellular structure like DNA, protein, lipid, and other cell parts. It causes disturbance in homeostasis of body leading to disease condition.<ref>Sharma GN, Gupta G, Sharma P. A Comprehensive Review of Free Radicals, Antioxidants, and Their Relationship with Human Ailments. Crit Rev Eukaryot Gene Expr. 2018;28(2):139-154. doi:10.1615/CritRevEukaryotGeneExpr.2018022258</ref>

==== [[Ama]] and metabolic end products ====

==== [[Ama]] and metabolic end products ====

[[Ama]] formation occurs due to the accumulation of toxic or intermediate product of metabolism in the body termed as [[mala]]. These intermediate products are formed due to defect in the metabolism of protein, carbohydrate or lipid. Excessive uric acid is formed due to improper metabolism of protein which is hazardous to body tissue and joint structure. Lactic acid, acetone and ketone bodies are formed due to improper metabolism of carbohydrate and fats. Lack of insulin activity defunct carbohydrate metabolism and leads to formation of intermediate products in the body. This intermediate products act as [[ama]] and leads to many disease conditions.

[[Ama]] formation occurs due to the accumulation of toxic or intermediate product of metabolism in the body termed as [[mala]]. These intermediate products are formed due to defect in the metabolism of protein, carbohydrate or lipid. Excessive uric acid is formed due to improper metabolism of protein which is hazardous to body tissue and joint structure. Lactic acid, acetone and ketone bodies are formed due to improper metabolism of carbohydrate and fats. Lack of insulin activity defuncts carbohydrate metabolism and leads to formation of intermediate products in the body. These intermediate products act as [[ama]] and lead to many disease conditions.

'''Metabolic waste functions as [[ama]]''': Tissue nutrients after action of metabolism (dhatvagni) nourishes body tissues and part is formed as excretory product ([[mala]]). Accumulation of this metabolic waste beyond certain limits disrupts the [[dosha]] hemostasis, leads to formation of [[ama]]. Depending on the type of metabolic waste and predominance of [[dosha]] exhibits many diseases.  

'''Metabolic waste functions as [[ama]]''': Tissue nutrients after metabolic process (dhatvagni) nourishes body tissues and part is formed as excretory product ([[mala]]). Accumulation of this metabolic waste beyond certain limits disrupts the [[dosha]] hemostasis, leads to formation of [[ama]]. Depending on the type of metabolic waste and predominance of [[dosha]] exhibits many diseases.  

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=== Research theses done (M.D./Ph.D.(Ayurveda) research works) ===

=== Research theses done (M.D./Ph.D.(Ayurveda) research works) ===

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#Badeka B.P.(1964 ) : Aam vivechan. Institute for Post Graduate Teaching & Research in Ayurveda, Gujarat Ayurved University, Jamnagar.

#Badeka B.P.(1964 ) : Ama vivechana. Institute for Post Graduate Teaching & Research in Ayurveda, Gujarat Ayurved University, Jamnagar.

#Singh A. K. (1986) : Ama Vivecana. National Institute of Ayurveda,Jaipur.

#Singh A. K. (1986) : Ama Vivechana. National Institute of Ayurveda, Jaipur.

#Ramesh Babu D (1989) : A critical study of Āma and its possible biological correlation with reference to the effect of Pancakola Kashaya in their management. Faculty of Ayurveda, I.M.S.,B.H.U., Varanasi.

#Ramesh Babu D (1989) : A critical study of Ama and its possible biological correlation with reference to the effect of Pancakola Kashaya in their management. Faculty of Ayurveda, I.M.S.,B.H.U., Varanasi.

#Smart Rachana (1996) :  A .Concept of Dhatugata Āma and principles of management. Institute for Post Graduate Teaching & Research in Ayurveda, Gujarat Ayurved University, Jamnagar.

#Smart Rachana (1996) :  A .Concept of Dhatugata Ama and principles of management. Institute for Post Graduate Teaching & Research in Ayurveda, Gujarat Ayurved University, Jamnagar.

#Bishnupriya Mohanty( 2001): Concept of Manobhighatakara Bhavas on Āma Utpatti particular to Madhumeha (DM). Institute for Post Graduate Teaching & Research in Ayurveda, Gujarat Ayurved University, Jamnagar.

#Bishnupriya Mohanty( 2001): Concept of Manobhighatakara Bhavas on Ama Utpatti particular to Madhumeha (DM). Institute for Post Graduate Teaching & Research in Ayurveda, Gujarat Ayurved University, Jamnagar.

#Gaurav sharma (2001) : Ama-Free radical-Amavaat. Institute for Post Graduate Teaching & Research in Ayurveda, Gujarat Ayurved University, Jamnagar.

#Gaurav sharma (2001) : Ama-Free radical-Amavaat. Institute for Post Graduate Teaching & Research in Ayurveda, Gujarat Ayurved University, Jamnagar.

#Smita Choradiya(2002) : Aharvidhi vidhaan-Annavah and purishvah srotas-Tanmana bhunjit.  Institute for Post Graduate Teaching & Research in Ayurveda, Gujarat Ayurved University, Jamnagar.

#Smita Choradiya(2002) : Aharvidhi vidhaan-Annavah and purishvah srotas-Tanmana bhunjit.  Institute for Post Graduate Teaching & Research in Ayurveda, Gujarat Ayurved University, Jamnagar.

*[[Matrashiteeya Adhyaya]], [[Yajjah Purushiya Adhyaya]], [[Rasa Vimana]], [[Sharira Vichaya Sharira]], [[Grahani Chikitsa]], [[Ahara vidhi]], [[Agni]], [[Ama]]

*[[Matrashiteeya Adhyaya]], [[Yajjah Purushiya Adhyaya]], [[Rasa Vimana]], [[Sharira Vichaya Sharira]], [[Grahani Chikitsa]], [[Ahara vidhi]], [[Agni]], [[Ama]]

==References ==

==References ==