title: The amino acid sensor GCN2 biases macronutrient selection during aging.
abstract: OBJECTIVE
  Selection of a balanced diet has a determinant impact on human health. Individual food preferences involve socio-cultural as well as physiological factors and evolve during aging. In mammals, physiological mechanisms governing food choices appear to require the sensing of nutrient concentrations in diet. This is particularly the case for dietary amino acids that are sensed by the protein kinase GCN2. It has been reported that GCN2 is involved in the adaptive response to amino acid imbalanced diets at the level of food intake and lipid metabolism. Here, we hypothesized that GCN2 may play a role in macronutrient selection and its age-related changes.
  
  
  METHODS
  Two groups of wild-type and GCN2 knock-out mice were subjected to a food self-selection protocol at ages 6, 12, 18 and 24 months. During each test, mice were allowed to create their own diets by selecting between three separate food sources, each containing either protein, fat or carbohydrates.
  
  
  RESULTS
  Our results show that the absence of GCN2 had two main age-related effects. First, it exacerbated fat preference at the expense of carbohydrate consumption. Second, it prevented the increase in protein intake.
  
  
  CONCLUSIONS
  These findings indicate that, in omnivores, the GCN2 ancient pathway participates in the control of food preference.
authors: Unité Mixte de Recherche 1019, Unité de Nutrition Humaine, Institut National de la Recherche Agronomique, Centre de Clermont-Ferrand/Theix, 63122 Saint Genès Champanelle, France.
authors: Anne-Catherine
authors: AC
authors: Maurin
authors: Cédric
authors: C
authors: Chaveroux
authors: Sarah
authors: S
authors: Lambert-Langlais
authors: Valérie
authors: V
authors: Carraro
authors: Céline
authors: C
authors: Jousse
authors: Alain
authors: A
authors: Bruhat
authors: Julien
authors: J
authors: Averous
authors: Laurent
authors: L
authors: Parry
authors: David
authors: D
authors: Ron
authors: Josette
authors: J
authors: Alliot
authors: Pierre
authors: P
authors: Fafournoux
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