title: Metabolic effects of mental stress during over- and underfeeding in healthy women.
abstract: OBJECTIVE
  To assess the short-term consequences of carbohydrate or fat overfeeding or of food restriction on the metabolic effects of mental stress in healthy lean women.
  
  
  METHODS
  The effects of a sympathetic activation elicited by mental stress were evaluated in a group of healthy women after standardized isocaloric feeding (ISO) or after a 3-day overfeeding with 40% excess calories as either carbohydrate overfeeding (CHO OF) or fat overfeeding (FAT OF). Oxygen consumption rate (VO(2)) was measured as an index of energy expenditure, and subcutaneous glycerol concentrations were monitored with microdialysis. The same measurements were performed in another group of healthy women after ISO and after a 3-day period of underfeeding with a protein sparing modified fast (UF).
  
  
  RESULTS
  In all conditions, mental stress significantly increased heart rate, blood pressure, plasma norepinephrine and epinephrine concentrations, and VO(2), and produced a nonsignificant increase in subcutaneous glycerol concentrations. CHO OF and FAT OF did not alter the effects of mental stress on VO(2) and subcutaneous glycerol concentrations. In contrast, UF increased basal VO(2) but significantly reduced its stimulation by mental stress. UF also enhanced the increase in subcutaneous glycerol concentrations during mental stress.
  
  
  CONCLUSIONS
  UF reduces the stimulation of energy expenditure and enhances lipolysis during sympathetic activation. These adaptations may be involved in mobilization of endogenous fat while limiting weight loss. In contrast, short-term overfeeding fails to alter the sympathetic control of energy expenditure and lipolysis.
authors.affiliation: Institute of Physiology, University of Lausanne, Switzerland.
authors.forename: Gérald
authors.initials: G
authors.lastname: Seematter
authors.forename: Mirjam
authors.initials: M
authors.lastname: Dirlewanger
authors.forename: Valentine
authors.initials: V
authors.lastname: Rey
authors.forename: Philippe
authors.initials: P
authors.lastname: Schneiter
authors.forename: Luc
authors.initials: L
authors.lastname: Tappy
mesh_terms: D000328:Adult; D018753:Diet, Protein-Restricted; D004038:Diet, Reducing; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage; D004435:Eating / Q000502:physiology / Q000523:psychology*; D004734:Energy Metabolism / Q000502:physiology; D004837:Epinephrine / Q000097:blood; D005260:Female; D005990:Glycerol / Q000032:analysis; D006801:Humans; D009638:Norepinephrine / Q000097:blood; D010101:Oxygen Consumption; D013315:Stress, Psychological / Q000378:metabolism*; D013564:Sympathetic Nervous System / Q000502:physiology*
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D005990:Glycerol; D009638:Norepinephrine; D004837:Epinephrine