The addition of monosodium glutamate and inosine monophosphate-5 to high-protein meals: effects on satiety, and energy and macronutrient intakes

Br J Nutr. 2009 Sep;102(6):929-37. doi: 10.1017/S0007114509297212. Epub 2009 Mar 9.


In a fed and orally stimulated state, whether the addition of monosodium glutamate (MSG) (alone or in combination with inosine monophosphate-5 (IMP-5)) to a high-protein (HP) meal leads to early satiety and a difference in energy intake at a second course was investigated. Ten men and twelve women consumed, in random order, a first-course meal consisting of: (1) water (control); (2) a HP meal with 0.6% MSG and 0.25% IMP-5; (3) a HP meal with no additives; (4) a HP meal with MSG only; (5) a sham-fed meal 2 (oral-stimulation). Appetite perceptions, plasma concentrations of glucagon-like peptide 1 (GLP-1), glucose and insulin, and energy intake at a buffet (i.e. a second course) were measured before and after each condition. Changes in appetite, and in GLP-1, glucose and insulin, were similar for the three fed HP conditions and all were greater (post hoc all P < 0.01) than the control and sham conditions. Energy intake was not different following the HP+MSG+IMP (1.86 (SEM 0.3) MJ) as compared with the HP+MSG-only (2.24 (SEM 0.28) MJ) condition (P = 0.08), or for the HP+MSG+IMP compared with the HP no-additives condition (1.60 (SEM 0.29) MJ) (P = 0.21). Following the HP+MSG-only condition, 0.64 (SEM 0.20) MJ more energy was consumed compared with the HP no-additives condition (P = 0.005). We conclude that the addition of MSG to a HP meal does not influence perceptions of satiety and it may increase energy intake at a second course. Cephalic responses after the sham condition were of similar magnitude to the control and therefore just tasting food is not enough to influence appetite and energy intake.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Blood Glucose / metabolism
  • Cross-Over Studies
  • Dietary Carbohydrates / administration & dosage
  • Dietary Fats / administration & dosage
  • Dietary Proteins / administration & dosage*
  • Energy Intake / drug effects*
  • Female
  • Food Additives / pharmacology*
  • Glucagon-Like Peptide 1 / blood
  • Humans
  • Inosine Monophosphate / pharmacology*
  • Insulin / blood
  • Male
  • Middle Aged
  • Satiation / drug effects*
  • Single-Blind Method
  • Sodium Glutamate / pharmacology*
  • Young Adult


  • Blood Glucose
  • Dietary Carbohydrates
  • Dietary Fats
  • Dietary Proteins
  • Food Additives
  • Insulin
  • Inosine Monophosphate
  • Glucagon-Like Peptide 1
  • Sodium Glutamate