Limits to sustained energy intake. XXX: Constraint or restraint? Manipulations of food supply show peak food intake in lactation is constrained

Zhi Jun Zhao (Corresponding Author), Davina Derous, Abby Gerard, Jing Wen, Xue Liu, Song Tan, Catherine Hambly, John Speakman* (Corresponding Author)

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

Lactating mice increase food intake 4-5 fold, reaching an asymptote in late lactation. A key question is whether this asymptote reflects a physiological constraint, or a maternal investment strategy (a ‘restraint’). We exposed lactating mice to periods of food restriction, hypothesizing that if the limit reflected restraint they would compensate by breaching the asymptote when refeeding. In contrast, if it was a constraint they would by definition be unable to increase their intake on refeeding days. Using isotope methods we found that during food restriction the females shut down milk production impacting offspring growth. During refeeding food intake and milk production rose again, but not significantly above unrestricted controls. Hypothalamic transcriptome profiling showed that following restriction lactating mice did not upregulate transcription of genes in the hunger signaling network, suggesting this may impose the constraint. These data provide strong evidence that asymptotic intake in lactation reflects a physiological/physical constraint, rather than restraint. Because hypothalamic neuropeptide Y (Npy) was upregulated under both states of restriction this suggests the constraint is not imposed by limits in the capacity to upregulate hunger signaling (the saturated neural capacity hypothesis). Understanding the genetic basis of the constraint will be a key future goal and will provide us additional information on the nature of the constraining factors on reproductive output, and their potential links to life history strategies.

Original languageEnglish
Article numberjeb208314
Number of pages19
JournalJournal of Experimental Biology
Volume223
Issue number8
Early online date16 Apr 2020
DOIs
Publication statusPublished - Apr 2020

Keywords

  • food restriction
  • daily energy intake (DEI)
  • heat dissipation limit (HDL) theory
  • milk energy output (MEO)
  • gene expression profile
  • hunger signaling
  • peripheral limitation
  • Swiss mice
  • neuropeptide Y
  • RNAseq
  • Neuropeptide Y
  • Daily energy intake (DEI)
  • Food restriction
  • Heat dissipation limit (HDL) theory
  • Gene expression profile
  • Peripheral limitation
  • Hunger signalling
  • Milk energy output (MEO)
  • SHORT-TERM CALORIE
  • GENE-EXPRESSION
  • METABOLIC-RATE
  • LABORATORY MICE
  • PROTEIN RESTRICTION
  • HEAT DISSIPATION CAPACITY
  • BODY-TEMPERATURE
  • BRANDTS VOLES
  • PHYSICAL-ACTIVITY
  • GRADED-LEVELS

Fingerprint Dive into the research topics of 'Limits to sustained energy intake. XXX: Constraint or restraint? Manipulations of food supply show peak food intake in lactation is constrained'. Together they form a unique fingerprint.

  • Cite this