Incubation of food craving is independent of macronutrient composition.

Rebecca A Darling,Travis E Brown,Kevin C Schlidt,Paige M Dingess,Erin M Smith

doi:10.1038/srep30900

Abstract

Cues previously paired with rewarding stimuli induce a time-dependent increase in the motivational craving state (incubation of craving). Whether there is an increase in craving for high-fat (HF) food over time, which may contribute to overeating and obesity, has not been determined. We hypothesized that cues paired with HF pellets would elicit a greater incubation of craving effect than those paired with standard chow (SC) pellets. Rats exposed to cues associated with either HF or SC pellets demonstrated equivalent levels of craving over an abstinence period of 30 days. Diet preference tests between SC pellets and LabDiet revealed that SC pellets were preferred over LabDiet. Rats reared on SC pellets exclusively, did not display incubation of craving for SC pellets, suggesting that prior history with the food plays an important role in cue-induced seeking behavior. Results identified cues previously associated with food undergo a comparable magnitude of incubation of craving. When ingestive behavior was measured after 30 days of abstinence, rats significantly increased their consumption of HF pellets. Our results indicate that food cues gain importance over time, trigger increased approach behaviors, and increased consumption of HF food following abstinence. This may contribute to overeating and the development of obesity.

Highlights

Environmental cues, which can manifest in many forms, are vastly important for driving behavior
The preference for the HF pellets persisted over the abstinence period (consumption in grams: HF = 4.70 ± 0.70 vs standard chow (SC) = 0.60 ± 0.20; t (14) = 5.41, p < 0.05, Fig. 1C). The rats increased their consumption of HF pellets from the last training day to the test day (training day 10: 2.80 ± 0.30 compared to 4.70 ± 0.70; t (14) = 3.26, p < 0.05, Fig. 1C)
In rodent self-administration models of addiction, it is suggested that an increase in approach behavior for drug-associated cues is reflective of an enhanced motivation to acquire that drug, and models “craving”[4]

Summary

Introduction

Environmental cues, which can manifest in many forms, are vastly important for driving behavior. To further investigate this finding, we utilized a SC pellet-raised control, in which animals were exclusively reared on SC pellets from weaning onward, rather than the standard LabDiet These animals did not exhibit an incubation of craving effect for SC pellets, evidenced by the lack of increase in lever responding from Test 1 to Test 2, suggesting that reward value is critical to the development of this phenomenon. Both SC and HF paired-cues induced equivalent levels of incubation, only HF elicited a time-dependent increase in consumption. Together our results indicate that while food cues gain importance over time, regardless of macronutrient composition, exposure to HF following a period of abstinence is sufficient to increase consumption, which may underlie challenges in dieting and facilitate the development of obesity

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Conclusion