Fat rather than sugar diet leads to binge-type eating, anticipation, effort behavior and activation of the corticolimbic system

ABSTRACT

Objectives: One factor contributing to the development of obesity is overeating palatable food. The palatability of food is driven by specific energy yielding combinations and flavor profiles that may contribute to its overconsumption. In rodents, restricted access to palatable food (PF) is a strong stimulus to trigger binge-type eating behavior (BTE), food anticipatory activity (FAA), effort behaviors and withdrawal symptoms. This is accompanied by plastic changes in corticolimbic areas associated with motivation and reward responses. Palatable food contains mainly a mixture of fat and sugar, thus, the contribution of each macronutrient for the behavioral and neuronal changes is unclear.

Methods: In this study, Wistar rats were exposed to restricted access to 50% fat rich diet (FRD) or 50% sugar rich diet (SRD) in order to compare the intensity of BTE, FAA, effort behaviors and withdrawal responses.

Results: In corticolimbic areas, c-Fos activation and ΔFosB accumulation were evaluated. After an acute exposition, rats ate more SRD than FRD, but FDR stimulated higher c-Fos. After chronic administration, the FDR group exhibited higher levels of BTE and FAA; this was associated with higher c-Fos and accumulation of ΔFosB in the corticolimbic system. Similar effects in the FRD group were observed after one week of withdrawal.

Discussion: Present data indicate that the fat rich diet is a stronger stimulus than the sugar rich diet for the development of wanting behavior for reward and the underlying plastic changes in the corticolimbic system. The differential effects may be due to the differing caloric density of the diets.

KEYWORDS:

• ΔFosB
• binge-type eating
• corticolimbic system
• fat rich diet
• sugar rich diet
• Palatable food
• effort behavior
• anticipatory activity

Acknowledgements

Estefania Espitia-Bautista is a doctoral student from Programa de Doctorado en Ciencias Biomédicas, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM) and received fellowship from CONACYT, No. de becario. 296682. CVU: 559045.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by DGAPA-PAPIIT UNAM IG-200417 and CONACyT 239403 to CE.

Notes on contributors

Estefania Espitia-Bautista

Estefania Espitia-Bautista obtained a degree in Psychology in 2013 from Facultad de Psicologia, Universidad Nacional Autónoma de México (UNAM) and now she is a doctoral student from Programa de Doctorado en Ciencias Biomédicas, Facultad de Medicina, UNAM. She has published 3 scientific papers, one as first author.

Carolina Escobar

Carolina Escobar is a Senior Professor in the Department of Anatomy, at the Faculty of Medicine, National Autonomous University in Mexico and directs a laboratory for basic research on Circadian Rhythms, Food intake and Metabolism. She studied Physiological Psychology followed by a masters and PhD in Physiological Sciences. The main contributions of her laboratory have been (1) on the behavioral, metabolic and brain mechanisms associated with food entrainment and (2) the development of experimental models of shift work in order to better understand the adverse effects of circadian disruption. Her group described mechanisms of circadian entrainment by palatable food, which now can partly explain addictive behavior. Her data on circadian disruption have provided evidence of the negative effects of food and activity during the rest phase, which has provided a new insight of the circadian system as a key process for homeostasis and for metabolic health. In this field she has published more than 90 scientific articles, 2 books and more than 25 book chapters. Since 2010 she is chief of the Research section in the Anatomy department. She is member of the Mexican Academy of Sciences and of the Mexican Academy of Medicine.