Measuring meals: structure of prandial food and water intake of rats. Am J Physiol Regul Integr Comp Physiol 2005 Jun;288(6):R1450-67
Date
01/08/2005Pubmed ID
15637168DOI
10.1152/ajpregu.00175.2004Scopus ID
2-s2.0-19344366414 (requires institutional sign-in at Scopus site) 125 CitationsAbstract
Attempts to understand ingestion have sought to understand the control of meals. The present study evaluated a meal definition that included prandial drinking (drinking-explicit meals). The spontaneous nocturnal intake of male Wistar rats was studied. The meal breakpoint was defined as the interval between feeding or drinking events providing the most stable estimate of meal structure. Alternative breakpoints derived from prevailing methodology, log-survivorship, or frequency histogram analysis of interfeeding intervals without respect to drinking were compared (drinking-naive meals). Threshold interfeeding intervals that accounted for drinking indirectly were evaluated as surrogate breakpoints (drinking-implicit meals). Definitions were compared by determining which criterion better conformed to predictions of satiety. Microstructural differences resulting from the definitions were also studied. Under the drinking-explicit definition, rats averaged nine or ten 13-min meals/night, during which they consumed food and water equally in duration (5-6 min) and quantity (2.3 g). Individual differences were observed in microstructure measures. Meals defined by drinking-informed, but not drinking-naive, methods were followed by the behavioral satiety sequence and by an initially low likelihood of resuming feeding that monotonically increased with time. The drinking-explicit definition uniquely revealed preprandial and postprandial correlations of similar magnitude. Under drinking-informed definitions, food restriction increased meal size, whereas drinking-naive definitions increased meal frequency. Drinking-implicit definitions provided workable approximations of meal frequency and size but inferior estimates of feeding duration, eating rate, and the preprandial correlation. Thus log-survivorship analysis is not appropriate for identifying meal breakpoints, and the consideration of drinking in meal definitions can provide a better estimate of meal structure.
Author List
Zorrilla EP, Inoue K, Fekete EM, Tabarin A, Valdez GR, Koob GFAuthor
Eva M. Fekete PhD Research Scientist I in the Physiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AlgorithmsAnimals
Circadian Rhythm
Drinking
Eating
Factor Analysis, Statistical
Food Deprivation
Individuality
Male
Rats
Rats, Wistar
Satiety Response
Time Factors
Videotape Recording
