-
[show abstract]
[hide abstract]
ABSTRACT: Hedonic eating differentiates from homeostatic eating on two main aspects: the first one is that eating occurs when there is no need for calorie ingestion and the second one is that the food is consumed exclusively for its gustatory and rewarding properties. Gastroeneteric hormones such as ghrelin, colecystokinin-33 (CCK) and peptide YY(3-36) (PYY(3-36)) are known to play a pivotal role in the homeostatic control of food intake. To the contrary, their role in hedonic eating has been never investigated. Here we report peripheral responses of CCK, PYY(3-36) and ghrelin to the consumption of food for pleasure in well-nourished satiated healthy subjects. Plasma levels of CCK, PYY(3-36) and ghrelin were measured in 7 satiated healthy subjects before and after ad libitum consumption of both a highly pleasurable food (hedonic eating) and an isoenergetic non-pleasurable food (non-hedonic eating). The consumption of food for pleasure was associated to a significantly increased production of the hunger hormone ghrelin and a significantly decreased secretion of the satiety hormone CCK. No significant changes in plasma PYY(3-36) levels occurred in the two eating conditions. These preliminary data demonstrate that in hedonic eating the peripheral hunger signal represented by ghrelin secretion is enhanced while the satiety signal of CCK production is decreased. This could be responsible for the persistence of peripheral cues allowing a continued eating as well as for the activation of endogenous reward mechanisms, which can drive food consumption in spite of no energy need, only for reward.
Psychoneuroendocrinology 01/2013; · 5.81 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Background: Stress is a precipitating factor for both binge eating and bulimia nervosa (BN); however, the biological mechanisms through which it may trigger binge eating are poorly understood. There is evidence that the adrenal hormone cortisol and the gastric peptide ghrelin might be involved in stress-induced food ingestion. We hypothesized that symptomatic patients with BN might disclose deranged responses of ghrelin and/or cortisol to stressors and that this could be related to their binge-eating behaviour. Methods: Here we investigated salivary cortisol and ghrelin responses to the Trier Social Stress Test (TSST) in 10 women with acute BN and 10 age-matched healthy females. Eating-related psychopathology and behaviours were assessed by self-report measures. Results: No significant differences emerged between bulimic patients and healthy controls in the pre-stress salivary levels of both cortisol and ghrelin. The BN patients displayed normal cortisol but enhanced ghrelin responses to TSST. No significant correlations emerged between stress-induced salivary hormone changes and self-report measures of binge eating. Conclusion: To our knowledge, this is the first study showing deranged salivary ghrelin reactivity to a psychosocial stressor in symptomatic patients with BN. The extent to which this could contribute to the binge-eating behaviour of BN subjects awaits clarification.
Neuropsychobiology 10/2012; 66(4):230-236. · 2.67 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Hedonic hunger refers to consumption of food just for pleasure and not to maintain energy homeostasis. In this condition, the subject eats also when not in a state of short-term energy depletion, and food is consumed uniquely because of its gustatory rewarding properties. The physiological mechanisms underlying this eating behavior are not deeply understood, but endogenous rewarding mediators like ghrelin and endocannabinoids are likely involved.
To explore the role of these substances in hedonic eating, we measured changes in their plasma levels in eight satiated healthy subjects after ad libitum consumption of highly palatable food as compared with the consumption of nonpalatable food in isoenergetic amounts with the same nutrient composition of the palatable food.
The consumption of food for pleasure was characterized by increased peripheral levels of both the peptide ghrelin and the endocannabinoid 2-arachidonoyl-glycerol. Levels of the other endocannabinoid anandamide and of anandamide-related mediators oleoylethanolamide and palmitoylethanolamide, instead, progressively decreased after the ingestion of both highly pleasurable and isoenergetic nonpleasurable food. A positive correlation was found between plasma 2-arachidonoyl glycerol and ghrelin during hedonic but not nonhedonic, eating.
The present preliminary findings suggest that when motivation to eat is generated by the availability of highly palatable food and not by food deprivation, a peripheral activation of two endogenous rewarding chemical signals is observed. Future research should confirm and extend our results to better understand the phenomenon of hedonic eating, which influences food intake and, ultimately, body mass.
The Journal of clinical endocrinology and metabolism 03/2012; 97(6):E917-24. · 6.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Abstract Objectives. The evidence that the activity of the sympathetic nervous system (SNS) is decreased in acute anorexia nervosa (AN) is not consistent. Therefore, we aimed to assess the SNS basal activity in malnourished AN patients through the measurement of diurnal salivary levels of α-amylase, whose secretion is regulated by the SNS. As secondary aim, we measured also salivary cortisol. Methods. Eight symptomatic female patients with restrictive AN and eight age-matched healthy women underwent saliva sample collection at awakening and over the day. α-amylase and cortisol were assayed by ELISA method. Results. In both patients and controls, saliva α-amylase levels significantly decreased during 60 min after awakening and then progressively rose towards the afternoon/evening. AN patients exhibited significantly reduced levels of the salivary enzyme with a significant decrease in its overall diurnal secretion and a dysregulated secretory pattern. As compared to control women, AN patients exhibited significantly enhanced levels of salivary cortisol at awakening, an enhanced and advanced cortisol secretion after awakening but no significant change in the overall diurnal secretion of the salivary hormone. Conclusions. These results suggest that the activity of the SNS, evaluated through the assessment of the diurnal secretion of salivary α-amylase, is impaired in the acute phase of AN whereas the cortisol awakening response is enhanced.
10/2011; 12(6):455-461.
-
[show abstract]
[hide abstract]
ABSTRACT: The evidence that the activity of the sympathetic nervous system (SNS) is decreased in acute anorexia nervosa (AN) is not consistent. Therefore, we aimed to assess the SNS basal activity in malnourished AN patients through the measurement of diurnal salivary levels of α-amylase, whose secretion is regulated by the SNS. As secondary aim, we measured also salivary cortisol.
Eight symptomatic female patients with restrictive AN and eight age-matched healthy women underwent saliva sample collection at awakening and over the day. α-amylase and cortisol were assayed by ELISA method.
In both patients and controls, saliva α-amylase levels significantly decreased during 60 min after awakening and then progressively rose towards the afternoon/evening. AN patients exhibited significantly reduced levels of the salivary enzyme with a significant decrease in its overall diurnal secretion and a dysregulated secretory pattern. As compared to control women, AN patients exhibited significantly enhanced levels of salivary cortisol at awakening, an enhanced and advanced cortisol secretion after awakening but no significant change in the overall diurnal secretion of the salivary hormone.
These results suggest that the activity of the SNS, evaluated through the assessment of the diurnal secretion of salivary α-amylase, is impaired in the acute phase of AN whereas the cortisol awakening response is enhanced.
The World Journal of Biological Psychiatry 07/2011; 12(6):455-61. · 2.38 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To characterize factors associated to diagnostic crossover from anorexia nervosa restricting type (ANR) and anorexia nervosa binge-purging type (ANBP) to bulimia nervosa (BN) and to compare BN individuals with initial ANR or ANBP to subjects with stable BN.
Two hundred thirty-eight patients with current and lifetime diagnosis of AN or BN underwent diagnostic, psychopathological, and historical examinations by means of ad hoc clinical interviews and rating scales.
One hundred twenty-three individuals had a stable BN. Seventy patients had a diagnosis of ANR and 45 of ANBP at the time of disease onset; 24 ANR patients and 23 ANBP subjects developed BN, whereas 46 ANR patients and 22 ANBP subjects did not crossover. Although the rate of diagnostic crossover was higher in the ANBP group than in the ANR one, the difference was not statistically significant. Longer illness duration, higher maximum past body mass index (BMI), higher novelty seeking, and lower self-directedness resulted significantly associated to crossover from ANR to BN, whereas higher maximum past BMI, higher desired body weight, higher novelty seeking, and lower harm avoidance were significantly associated to crossover from ANBP to BN. As compared to stable BN subjects, BN patients with initial ANR exhibited lower minimum past BMI, lower desired body weight, higher drive for thinness, ascetism, and social insecurity scores; BN patients with initial ANBP exhibited lower minimum past BMI and decreased enteroceptive awareness scores.
Different clinical and personality factors seem to be associated to crossover from ANR and ANBP to BN. Moreover, BN with initial ANR seems to differ clinically from stable BN. These findings may have therapeutic and prognostic implications.
Comprehensive psychiatry 52(1):56-62. · 2.08 Impact Factor
