Fat Preference: A Novel Model of Eating Behavior in Rats

Abstract

Obesity is a growing problem in the United States of America, with more than a third of the population classified as obese. One factor contributing to this multifactorial disorder is the consumption of a high-fat diet, a behavior that has been shown to increase both caloric intake and body fat content. However, the elements regulating preference for high-fat food over other foods remain understudied. To overcome this deficit, a model to quickly and easily test changes in the preference for dietary fat was developed. The Fat Preference model presents rats with a series of choices between foods with differing fat content. Like humans, rats have a natural bias toward consuming high-fat food, making the rat model ideal for translational studies. Changes in preference can be ascribed to the effect of either genetic differences or pharmacological interventions. This model allows for the exploration of determinates of fat preference and screening pharmacotherapeutic agents that influence acquisition of obesity.

Binge-Type Eating in Rats is Facilitated by Neuromedin U Receptor 2 in the Nucleus Accumbens and Ventral Tegmental Area

“…We used an animal model of binge-type eating to quantify binge intake in rats. This model only simulated a binge episode, similar to that observed in BED and obesity [ 27 , 29 , 30 , 32 , 33 , 35 ]. One of the major limitations of our study is the inability of our model to replicate all clinical aspects of BED.…”

“…However, energy-dense diets are reinforcing and are significantly preferred by rodents. The fat–carbohydrate mixtures were designed to contain the preferred higher energy density, which promotes overeating and improves the translational relevance in which humans binge on energy-dense foods [ 13 , 35 , 51 , 52 , 53 ].…”

“…Our binge-type eating protocol was based on previously published models [ 27 , 29 , 32 , 33 , 35 ]. Briefly, male Sprague-Dawley rats ( n = 10) were maintained on a diet of normal chow (17% fat by kcal) and water.…”

“…Models of binge-type eating have been validated in rodents, demonstrating success in studying the overconsumption behavior characteristic of both BED and obesity [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ]. The intermittent access model provides ad libitum access to regular chow and water, with limited presentation of a highly palatable food, which simulates a binge episode, similar to that observed in BED and obesity [ 27 , 29 , 30 , 32 , 33 , 35 ]. While this model can recreate and quantify food intake during a binge episode, it does not replicate the psychological aspects of BED, such as feelings of loss of control and feelings of shame and guilt [ 2 , 3 , 4 , 5 ].…”

The Development of Nonalcoholic Fatty Liver Disease and Metabolic Syndromes in Diet-Induced Rodent Models

“…Most digestible carbs have 4 kcal of accessible energy per gram, whereas fat provides 9 kcal per gram [ 39 ]. However, since the diets were prepared differently, the control diet was given in the form of pellets from Research Diets, while all the other diets were freshly made daily as pellets [ 40 ]. As a result, changes in the meal consistencies may have resulted in variances in their food consumption compared to that of the control group.…”