Anorexia Essay Conclusion
The biochemical and physiological adaptations that result from a lack of food help to preserve physiological function in order to maintain behaviors like food seeking or predator avoidance and also, to resume all metabolic processes necessary when food becomes available.
However, absolute or long term food deprivation observed in nature or in restrictive AN proceeds in stages in which the individual/organism tries to adapt its metabolism to energy costs but that culminates in death, due to exhaustion of energy stores. (2006), the different stages progress from fasting to starvation, but “The demarcation between these two states is rarely appreciated, perhaps owing to lack of definition.
In a recent review (Garcia et al., 2011), the lifetime prevalence of AN was estimated to be 1.9% in female adults to 2.6% in female adolescents in industrialized countries. Difference in susceptibility to activity-based anorexia in two inbred strains of mice.
In the binge eating/purging subtype, the individual engages in recurrent episodes of binge eating or purging behavior while such episodes do not occur in the restricting subtype.
A better understanding of the role of this gastric hormone in dysfunctional AN like feeding behavior is important when evaluating its therapeutic potential for the treatment of AN, envisaged to be used alongside mainstay psychiatric and nutritional therapies.
Chronic food restriction is linked to several disorders classified in DSM-V (Diagnostic and Statistical Manuel of Mental Disorders).
In humans, fasting often refers to abstinence from food, whereas starvation is used for a state of extreme hunger resulting from a prolonged lack of essential nutrients. Constitutional thinness and lean anorexia nervosa display opposite concentrations of peptide YY, glucagon-like peptide 1, ghrelin, and leptin.
In other words, starving is a state in which an animal, having depleted energy stores, normally would feed to continue normal physiological processes.” Briefly, three metabolic phases are described during food deprivation (Wang et al., 2006) where energy metabolic adaptations occur to allow supply of fuel in the different parts of the organism, especially the brain (see Table 1).
Moreover, AN is increasingly recognized as an addictive behavior disorder. In regard to these metabolic stages, the transition from fasting to starvation occurs by the end of phase II or the beginning of phase III. Pubmed Abstract | Pubmed Full Text | Cross Ref Full Text Germain, N., Galusca, B., Grouselle, D., Frere, D., Tolle, V., Zizzari, P., et al. Ghrelin/obestatin ratio in two populations with low bodyweight: constitutional thinness and anorexia nervosa. Pubmed Abstract | Pubmed Full Text | Cross Ref Full Text Germain, N., Galusca, B., Le Roux, C. Thus, voluntary anorexia as seen in restrictive AN should correspond to phases I and II. *-Indeed, many of its common primary characteristics – food obsession coupled with food restriction, weight loss, heightened physical activity, and the strong association with mood disorder (such as anxiety or depression), strongly suggest a potential alteration of the central (dopaminergic) reward system. Anorexia nervosa patients exhibit significant changes in the release of key hormones involved in energy balance and feeding control (Hasan and Hasan, 2011). The severe weight loss observed in AN patients is accompanied by significant changes in hormones involved in energy balance, feeding behavior, and bone formation, all of which can be replicated in animals models. Increasing evidence suggests that AN could be an addictive behavior disorder, potentially linking defects in the reward mechanism with suppressed food intake, heightened physical activity, and mood disorder. Pubmed Abstract | Pubmed Full Text | Cross Ref Full Text Gniuli, D., Liverani, E., Capristo, E., Greco, A. Feeding is a behavior that ensures an adequate and varied supply of nutritional substrates essential to maintain energy levels for basal metabolism, physical activity, growth, and reproduction and hence, for survival of every living organism on Earth. In the case of mammals, that must maintain a stable body temperature, the maintenance of a high metabolic rate requires constant availability of a sufficient amount of energy stores. Pubmed Abstract | Pubmed Full Text | Cross Ref Full Text Gnanapavan, S., Kola, B., Bustin, S. The increases in plasma ghrelin levels in AN seem paradoxical in light of the restrained eating adopted by these patients and suggest an adaptive response to the disease. Leptin, neuropeptide Y, and peptide YY in long-term recovered eating disorder patients. In regard to the metabolic deficiencies occurring in restrictive AN (see infra), the aim of this review is to highlight the impact of ghrelin in the adaptation of the organism to chronic food restriction until it falls into exhaustion and death.