PMID- 17990972
OWN - NLM
STAT- MEDLINE
DCOM- 20080221
LR  - 20071226
IS  - 1549-1684 (Print)
IS  - 1549-1684 (Linking)
VI  - 10
IP  - 4
DP  - 2007 Dec
TI  - Hunger does not diminish over time in mice under protracted caloric restriction.
PG  - 533-42
AB  - Caloric restriction (CR) is the only nongenetic manipulation known to reliably 
      prolong life-span. Modeling suggests that humans would need to restrict their 
      intake for many years to reap any lifespan benefits. The feasibility of such 
      prolonged restriction may hinge on whether hunger diminishes with the time period 
      spent restricted. We used the magnitude of hyperphagia on release from 
      restriction as a bioassay of hunger in restricted mice. During restriction, mice 
      develop a characteristic pattern of neuropeptide signals in the arcuate nucleus 
      that reflect their hunger. This pattern is normalized after the postrestriction 
      hyperphagia, validating hyperphagia as an indicator of the hunger during 
      restriction. Mice were food restricted (80% of ad lib.) for 50 days. They 
      initially lost weight, but then became weight stable and were maintained in CR at 
      this lower level of energy balance for between 0 and 50 days and were then fed ad 
      lib. for 50 days. When released onto ad lib. food, the magnitude of the 
      hyperphagic response was independent of the prior length of CR. Hyperphagia ended 
      when body mass was normalized. Hunger therefore did not diminish even when they 
      were restricted for 100 days, equivalent to about 11 years in humans. The pattern 
      of hyperphagic response suggested that signals coding body mass drive hunger 
      during restriction, and because body mass under restriction remains depressed, 
      this suggests that hunger would never disappear, making restriction to prolong 
      lifespan in humans difficult to accomplish.
FAU - Hambly, Catherine
AU  - Hambly C
AD  - Aberdeen Centre for Energy Regulation and Obesity (ACERO), Rowett Research 
      Institute, Bucksburn, Aberdeen, Scotland, United Kingdom. c.hambly@abdn.ac.uk
FAU - Mercer, Julian G
AU  - Mercer JG
FAU - Speakman, John R
AU  - Speakman JR
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Rejuvenation Res
JT  - Rejuvenation research
JID - 101213381
RN  - 0 (Neuropeptides)
RN  - 0 (RNA, Messenger)
SB  - IM
MH  - Animals
MH  - Body Weight
MH  - *Caloric Restriction
MH  - Hunger/*physiology
MH  - Hyperphagia
MH  - Mice
MH  - Neuropeptides/genetics
MH  - RNA, Messenger/analysis
MH  - Time Factors
EDAT- 2007/11/10 09:00
MHDA- 2008/02/22 09:00
CRDT- 2007/11/10 09:00
PHST- 2007/11/10 09:00 [pubmed]
PHST- 2008/02/22 09:00 [medline]
PHST- 2007/11/10 09:00 [entrez]
AID - 10.1089/rej.2007.0555 [doi]
PST - ppublish
SO  - Rejuvenation Res. 2007 Dec;10(4):533-42. doi: 10.1089/rej.2007.0555.