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Ingestion und Kognition - Der Einfluss von Antizipation, Perzeption und Schlafentzug auf die Nahrungsaufnahme

Fachliche Zuordnung Endokrinologie, Diabetologie, Metabolismus
Förderung Förderung von 2008 bis 2011
Projektkennung Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 5397495
 
Erstellungsjahr 2013

Zusammenfassung der Projektergebnisse

Our project focused on the relevance of cognitive processes and sleep for ingestive behavior and related endocrine patterns. Also, considering that insulin acts in the brain to restrict food intake but also to improve cognitive function, we further scrutinized the impact of centrally administered insulin on eating behavior and metabolism. In a series of experiments in healthy human subjects, we manipulated food anticipation by instructing fasted subjects that breakfast would or would not be served two hours later. This psychological intervention had a distinct two-fold effect on endocrine parameters. First, anticipating breakfast intake was associated with an increase in serum cortisol concentrations that continued to be visible when the announced food, contrary to expectations, was withdrawn. This finding could imply that dietary restraint, a behavior associated with habitually extended periods of anticipating food that is temporarily withheld, might be associated with detrimental effects on stress axis activity. In subjects who received breakfast after two hours of anticipation, we observed a marked reduction in postprandial concentrations of the orexigenic hormone ghrelin in comparison to subjects who had not expected to be served food. This result reflects the importance of subtle cognitive factors in endocrine regulation and also suggests that neurobehavioral approaches to improved food intake control should take into account meal anticipatory mechanisms. Recently finished and ongoing studies aim at the relationship between sweet perception and ingestive behavior as well as glucose homeostasis. The postprandial period of food intake was examined in experiments in healthy women who received intranasal insulin after ingestion of a standard meal to examine the contribution of the hormone to the processing of satiation. As hypothesized, central nervous insulin administration via the intranasal route intensified meal-related satiety and reduced subsequent snack intake, an effect that was not found when the peptide was administered in the fasted state. This pattern of results suggests that insulin acts as a satiety signal and furthermore questions the previously held assumption that women are less sensitive than men to the anorexigenic impact of the peptide. Related experiments comparing the effect of intranasal insulin between young and postmenopausal women indicate that in contrast to animal experiments, estrogen does not seem to modulate central nervous insulin processing in humans. Furthermore, we could demonstrate that intranasal insulin enhances postprandial thermogenesis and appears to exert insulin-sensitizing effects on peripheral blood glucose homeostasis. The latter effect could be of particular relevance with regard to future options in the treatment of diabetes. In experiments with an even stronger clinical outline, we could furthermore show that the insulin analogue detemir which is known to have a beneficial effect on body weight when given to diabetic patients, exerts a stronger anorexigenic and central nervous effect in healthy humans. Investigating the contribution of sleep-wake patterns to the ongoing control of food intake, we have found that partial sleep deprivation for two nights does not acutely increase calorie consumption but decreases physical activity, which might be one factor behind the epidemiological link between short sleep duration and obesity. Finally, related studies yielded evidence for an acute impairment in glucose homeostasis due to sleep loss.

Projektbezogene Publikationen (Auswahl)

 
 

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