Davis, Kristina W. (2008-05). Binge-eating behavior in mice: influences of restriction and palatability in a limited access model. Doctoral Dissertation. Thesis uri icon

abstract

  • 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.
  • 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.

publication date

  • May 2008