title: The effects of graded levels of calorie restriction: I. impact of short term calorie and protein restriction on body composition in the C57BL/6 mouse.
abstract: Faced with reduced levels of food, animals must adjust to the consequences of the shortfall in energy. We explored how C57BL/6 mice withdrew energy from different body tissues during three months of food restriction at graded levels up to 40% (calorie restriction: CR). We compared this to the response to equivalent levels of protein restriction (PR) without a shortfall in calories. Under CR there was a dynamic change in body mass over 30 days and thereafter it stabilized. The time to reach stability was independent of the level of restriction. At the end of three months whole body dissections revealed differential utilization of the different tissues. Adipose tissue depots were the most significantly utilized tissue, and provided 55.8 to 60.9% of the total released energy. In comparison, reductions in the sizes of structural tissues contributed between 29.8 and 38.7% of the energy. The balance was made up by relatively small changes in the vital organs. The components of the alimentary tract grew slightly under restriction, particularly the stomach, and this was associated with a parallel increase in assimilation efficiency of the food (averaging 1.73%). None of the changes under CR were recapitulated by equivalent levels of PR.
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK.
authors.forename: Sharon E
authors.initials: SE
authors.lastname: Mitchell
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK.
authors.forename: Zhanhui
authors.initials: Z
authors.lastname: Tang
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK.
authors.forename: Celine
authors.initials: C
authors.lastname: Kerbois
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK.
authors.forename: Camille
authors.initials: C
authors.lastname: Delville
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK.
authors.forename: Penelope
authors.initials: P
authors.lastname: Konstantopedos
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Bruel
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK.
authors.forename: Davina
authors.initials: D
authors.lastname: Derous
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK.
authors.forename: Cara
authors.initials: C
authors.lastname: Green
authors.affiliation: Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, UK.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Aspden
authors.affiliation: Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, UK.
authors.forename: Simon R
authors.initials: SR
authors.lastname: Goodyear
authors.affiliation: Key laboratory of Systems Biology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Luonan
authors.initials: L
authors.lastname: Chen
authors.affiliation: Chinese Academy of Sciences Key Laboratory of Computational Biology, Chinese Academy of Sciences, Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Jackie J D
authors.initials: JJ
authors.lastname: Han
authors.affiliation: State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang, Beijing, China.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Pathology and Department of Biology, University of Washington, Seattle, WA, USA.
authors.forename: Daniel E L
authors.initials: DE
authors.lastname: Promislow
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK.
authors.forename: David
authors.initials: D
authors.lastname: Lusseau
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK.
authors.forename: Alex
authors.initials: A
authors.lastname: Douglas
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK.|State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang, Beijing, China.
authors.forename: John R
authors.initials: JR
authors.lastname: Speakman
mesh_terms: D000818:Animals; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D031204:Caloric Restriction / Q000379:methods*; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000378:metabolism*; D002149:Energy Intake; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D004044:Dietary Proteins
keywords: Gerotarget; body composition; calorie restriction; dietary restriction; food intake; protein restriction