The effects of graded levels of calorie restriction: V. Impact of short term calorie and protein restriction on physical activity in the C57BL/6 mouse

// Sharon E. Mitchell 1 , Camille Delville 1 , Penelope Konstantopedos 1 , Davina Derous 1 , Cara L. Green 1 , Yingchun Wang 2 , Jing-Dong J. Han 3 , Daniel E.L. Promislow 4 , Alex Douglas 1 , Luonan Chen 5 , David Lusseau 1 and John R. Speakman 1,2 1 Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, Scotland, UK 2 State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang, Beijing, China 3 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 4 Department of Pathology and Department of Biology, University of Washington, Seattle, Washington, USA 5 Key Laboratory of Systems Biology, Innovation Center for Cell Signaling Network, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China Correspondence to: John R. Speakman, email: // Keywords : food intake, dietary restriction, protein restriction, calorie restriction, physical activity, Gerotarget Received : October 30, 2015 Accepted : February 28, 2016 Published : March 17, 2016 Abstract Calorie restriction (CR) delays the onset of age-related disease and extends lifespan in a number of species. When faced with reduced energy supply animals need to lower energy demands, which may be achieved in part by reducing physical activity (PA). We monitored changes in PA using implanted transmitters in male C57BL/6 mice in response to graded levels of CR (10 to 40%) or matched levels of graded protein restriction (PR) for 3 months. Mice were fed at lights out and ad libitum controls were limited to dark-phase feeding (12AL) or 24hr/day. Total daily PA declined in a non-linear manner over the first 30 days of CR or PR, remaining stable thereafter. Total daily PA was not related to the level of CR or PR. Total daily PA over the last 20 days of restriction was related to circulating leptin, insulin, tumor necrosis factor-α (TNF- α) and insulin-like growth factor (IGF)-1 levels, measured after 3 months. Mice under restriction showed a high level of activity in the 2hrs before feeding (food anticipatory activity: FAA). FAA followed a complex pattern, peaking around day 20, falling on ~day 37 then increasing again. FAA was also positively related to the level of restriction and inversely to leptin, insulin, TNF-α and IGF-1. Non-FAA, in contrast, declined over the period of restriction, generally more so in mice under greater restriction, thereby offsetting to some extent the increase in FAA. Mice under PR displayed no changes in PA over time or in comparison to 12AL, and showed no increase in FAA.