title: Umami flavor enhances appetite but also increases satiety.
abstract: BACKGROUND
  Monosodium glutamate (MSG) has been shown to increase satiety when combined with protein. Inosine 5'-monophosphate acts synergistically with MSG when tasted, is present in high-protein sources, and may potentially further enhance satiety.
  
  
  OBJECTIVE
  We assessed effects of a combination of monosodium glutamate and inosine 5'-monophosphate (MSG/IMP) provided either alone or in a high-energy, high-carbohydrate and -protein soup on appetite during ingestion and postingestive satiety.
  
  
  METHODS
  Fixed portions (450 g) of a low-energy control and high-energy, high-carbohydrate and -protein soup preload with added monosodium glutamate and inosine 5'-monophosphate (MSG/IMP+) or without added monosodium glutamate and inosine 5'-monophosphate (MSG/IMP-) were consumed on 4 nonconsecutive days, and changes in appetite during soup intake and at a subsequent ad libitum lunch were assessed in 26 low-restraint volunteers by using a within-participant design.
  
  
  RESULTS
  MSG/IMP+ conditions significantly reduced subsequent intake more than the MSG/IMP- condition did irrespective of energy. The high-carbohydrate and -protein condition also reduced intake independently of MSG/IMP. Energy compensation was greater in the MSG/IMP+ carbohydrate and protein conditions than MSG/IMP- condition. The addition of the MSG/IMP+ also increased the soup pleasantness and caused an immediate increase in appetite when the soup was first tasted.
  
  
  CONCLUSIONS
  The addition of MSG/IMP to a low-energy preload had a biphasic effect on appetite by stimulating appetite during ingestion and enhancing postingestive satiety.
authors.affiliation: From the School of Psychology, University of Sussex, Brighton, United Kingdom.
authors.forename: Una
authors.initials: U
authors.lastname: Masic
authors.affiliation: From the School of Psychology, University of Sussex, Brighton, United Kingdom.
authors.forename: Martin R
authors.initials: MR
authors.lastname: Yeomans
mesh_terms: D000293:Adolescent; D000328:Adult; D001067:Appetite Depressants / Q000378:metabolism; D001069:Appetite Regulation; D019167:Appetite Stimulants / Q000378:metabolism; D018592:Cross-Over Studies; D002149:Energy Intake; D004739:England; D005247:Feeding Behavior; D005260:Female; D005421:Flavoring Agents / Q000378:metabolism*; D005503:Food Additives / Q000378:metabolism*; D005518:Food Preferences; D006801:Humans; D007291:Inosine Monophosphate / Q000378:metabolism*; D062409:Lunch; D008297:Male; D019518:Postprandial Period; D012528:Satiety Response; D012970:Sodium Glutamate / Q000378:metabolism*; D013649:Taste; D055815:Young Adult
chemical_list: D001067:Appetite Depressants; D019167:Appetite Stimulants; D005421:Flavoring Agents; D005503:Food Additives; D007291:Inosine Monophosphate; D012970:Sodium Glutamate