title: Gross energy metabolism in mice under late onset, short term caloric restriction.
abstract: Late onset, short-term moderate caloric restriction (CR) may have beneficial health effects. A 26% CR regime induced at 14 months of age for 70 days in male C57Bl/6 (ICRFa) mice resulted in a reduction in body mass of 17%. A decrease in daily energy expenditure was associated with decreased body mass in CR mice. There was no difference in total levels of physical activity between the CR and ad libitum (AL) groups; however, activity patterns were different. We developed a Bayesian model to dissect the impact of food anticipation activity (FAA) and feeding on physical activity. FAA was stronger in CR mice and remaining basal activity was higher in AL mice, but CR mice displayed larger diurnal variations as well as a phase shift in their diurnal activity. CR mice displayed lower body temperature, especially late during the dark phase. This was due to lower basal (activity-independent) temperature at all times of the day, coupled to a phase shift in the diurnal rhythm. The correlation between body temperature and physical activity was independent of feeding regimen and light/dark cycles. Reduction of body mass and basal temperature were major compensatory mechanisms to reduced food availability during late-onset, short-term CR.
authors.affiliation: Centre for Integrated Systems Biology of Ageing and Nutrition, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK. kerry.cameron@newcastle.ac.uk
authors.forename: Kerry M
authors.initials: KM
authors.lastname: Cameron
authors.forename: Andrew
authors.initials: A
authors.lastname: Golightly
authors.forename: Satomi
authors.initials: S
authors.lastname: Miwa
authors.forename: John
authors.initials: J
authors.lastname: Speakman
authors.forename: Richard
authors.initials: R
authors.lastname: Boys
authors.forename: Thomas
authors.initials: T
authors.lastname: von Zglinicki
mesh_terms: D000375:Aging; D000818:Animals; D001481:Basal Metabolism; D001499:Bayes Theorem; D001831:Body Temperature; D031204:Caloric Restriction; D002149:Energy Intake; D004734:Energy Metabolism; D005247:Feeding Behavior; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009369:Neoplasms / Q000209:etiology; D013997:Time Factors; D016896:Treatment Outcome