Navegando por Palavras-chave "hyperphagia"

Agora exibindo 1 - 3 de 3
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    A reassessment of the hyperphagia/weight-loss paradox during sleep deprivation
    (Amer Academy Sleep Medicine, 2006-09-01) Martins, Paulo J. F. [UNIFESP]; D'Almeida, Vânia [UNIFESP]; Nobrega, Jose N.; Tufik, Sergio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Ctr Addict & Mental Hlth
    Study Objectives: Sleep deprivation is a well-known paradigm to investigate the deleterious effects of prolonged wakefulness. Previous studies have shown that, during sleep deprivation, rats are hyperphagic but, paradoxically, lose body weight. This phenomenon has been attributed to increased metabolism. However, most previous studies have failed to account for food spillage, which may be considerable during sleep deprivation.Design: In the present study, we revisited the issue of feeding changes in sleep-deprived rats and introduced different procedures to allow accurate estimation of food spillage prior to, during, and after 120 hours of sleep deprivation by a single platform technique.Setting: Animal Sleep Research Laboratory, Psychobiology Department, Universidade Federal de Sao Paulo, Brazil.Measurements and Results: The main finding was that, once corrected for spillage, food intake was not significantly increased during sleep deprivation. Increases in food removed from feeders were accompanied by proportional increases in food spillage, resulting in no net changes in food intake. Further, weight loss did occur during the sleep-deprivation period, especially in the first 24 hours, and it was actually explained by a reduction in food intake.Conclusion: The hyperphagia/weight-loss paradox previously seen during prolonged sleep deprivation does not necessarily occur with shorter periods of deprivation. Although we found no evidence of hyperphagia for up to 5 days of sleep deprivation in chow-fed rats, our data suggest that an impairment in the ability to increase food intake in response to increased energy expenditure contributes to the energy deficit during sleep deprivation in rats.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Sleep deprivation-induced gnawing - relationship to changes in feeding behavior in rats
    (Elsevier B.V., 2008-01-28) Martins, P. J. F. [UNIFESP]; Nobrega, J. N.; Tufik, S. [UNIFESP]; D'Almeida, V. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Ctr Addict & Mental Hlth
    We have recently reported that food spillage increases during sleep deprivation in rats, which may lead to an overestimation of food intake in this condition. the objective of this study was to verify whether sleep deprivation induces an increase in gnawing behavior that could account for increased food spillage and apparent increase in food intake. We introduced wood blocks as objects for gnawing and determined the effects of their availability on food consumption and food spillage during sleep deprivation. Wood block availability reduced the amount of food removed from hoppers and decreased the amount of food spilled. However, weight loss still occurred during the sleep deprivation period, especially in the first 24 h, and it was related to a reduction in food intake. Sleep deprivation causes an increase in stereotyped gnawing behavior which largely accounts for increased food spillage observed during deprivation. Specifically, the observed increase in food removed from feeders seems to be due to an increase in gnawing and not to increased hunger. However, even when appropriately corrected for spillage, food intake decreased in the first 24 h of sleep deprivation, which accounted for most of the body weight loss seen during the 96 h of sleep deprivation. (C) 2007 Elsevier Inc. All rights reserved.
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Type of diet modulates the metabolic response to sleep deprivation in rats
    (Biomed Central Ltd, 2011-12-12) Martins, Paulo J. F. [UNIFESP]; Fernandes, Leandro [UNIFESP]; Oliveira, Allan C. de [UNIFESP]; Tufik, Sergio [UNIFESP]; D'Almeida, Vania [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Background: Evidence suggests that sleep loss is associated with an increased risk of obesity and diabetes; however, animal models have failed to produce weight gain under sleep deprivation (SD). Previous studies have suggested that this discrepancy could be due to more extreme SD conditions in experimental animals, their higher resting metabolic rate than that of humans, and the decreased opportunity for animals to ingest high-calorie foods. Thus, our objective was to determine whether diets with different textures/compositions could modify feeding behavior and affect the metabolic repercussions in SD in rats.Methods: Three groups of male rats were used: one was designated as control, one was sleep deprived for 96 h by the platform technique (SD 96h) and one was SD 96h followed by a 24-h recovery (rebound). in the first experiment, the animals were fed chow pellets (CPs); in the second, they received high-fat diet and in the third, they were fed a liquid diet (LD).Results: We observed that SD induces energy deficits that were related to changes in feeding behavior and affected by the type of diet consumed. Regardless of the diet consumed, SD consistently increased animals' glucagon levels and decreased their leptin and triacylglycerol levels and liver glycogen stores. However, such changes were mostly avoided in the rats on the liquid diet. SD induces a wide range of metabolic and hormonal changes that are strongly linked to the severity of weight loss.Conclusions: the LD, but not the CP or high-fat diets, favored energy intake, consequently lessening the energy deficit induced by SD.