Animal models of bingeing have typically used stress to induce bingeing. A
recent model, limited-access to high-fat diet (HFD), has shown that caloric restriction
and stress were not required to induce bingeing in rats. This study replicated this model
in mice, explored the fat content within the model, and investigated locomotor activation
associated with binge-eating. Adult mice were maintained on a restricted feeding (RF)
schedule of 2 h/d of access to chow or ad lib access to chow, and then provided limited
access to 45% HFD or 84% HFD for 30 min 3 d/ week for 6 total snack sessions.
Circadian activity was monitored for RF animals offered 84% HFD, and after 6 snack
sessions were complete, allowed continuous access to the 45% HFD or the 84% HFD for
two weeks to explore rebound feeding. Bingeing, defined by increasing intakes across
days, was reported for mice offered 45% HFD regardless of deprivation state (RF or ad
lib), while mice offered 84% HFD only exhibited bingeing when they were restricted.
Comparison of male and female mice maintained RF, offered 45% HFD snack, showed that females had higher intake (kcals/g-bw) while ad lib fed mice exhibited no sex
differences. Circadian recordings for female RF mice offered 84% HFD showed shifts in
activity from the first hour of dark cycle to the hour preceding the snack and supported
that offering the HFD produced alterations in food-associated arousal. During rebound,
female RF mice given 84% HFD showed the highest intakes in week 1, and then
exhibited a marked decline in week 2. The week 1 intake for RF animals were to regain
lost body weight and that homeostatic-like intake in week 2 allowed normal body weight
maintenance.
Results of this investigation support human data that females are more
susceptible to binge-type eating disorder, shows that limited access to palatable foods for
females under caloric restriction induces changes in circadian activity, and reveals that
using mice in this model requires more investigation to optimize binge-behavior. Diet
comparisons also suggest that homeostatic and reward mechanisms may have an additive
effect on bingeing.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2821 |
| Date | 15 May 2009 |
| Creators | Davis, Kristina W. |
| Contributors | Wellman, Paul |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | electronic, application/pdf, born digital |
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