Original Research ARTICLE
Intake of an obesogenic cafeteria diet affects body weight, feeding behavior and glucose and lipid metabolism in a photoperiod-dependent manner in F344 rats
- 1Eurecat (Spain), Spain
- 2Nutrigenomics Research Group, Department of Biochemistry and Biotechnology, Rovira i Virgili University, Spain
We previously demonstrated that chronic exposure to different photoperiods induced marked variations in several glucose and lipid metabolism-related parameters in normoweight Fischer 344 (F344) rats. Here, we examined the effects of the combination of an obesogenic cafeteria diet (CAF) and the chronic exposure to three different day lengths (L12, 12 h light/day; L18, 18 h light/day and L6, 6 h light/day) in this rat strain. Although no changes were observed during the first 4 weeks of adaptation to the different photoperiods in which animals were fed a standard diet, the addition of the CAF for the subsequent 7 weeks triggered profound physiologic and metabolic alterations in a photoperiod-dependent manner. Compared with L12 rats, both L6 and L18 animals displayed lower body weight gain and cumulative food intake in addition to decreased energy expenditure and locomotor activity. These changes were accompanied by differences in food preferences and by a sharp upregulation of the orexigenic genes Npy and Ghsr in the hypothalamus, which could be understood as a homeostatic mechanism for increasing food consumption to restore body weight control. L18 rats also exhibited higher glycemia than the L6 group, which could be partly attributed to the decreased pAkt2 levels in the soleus muscle and the downregulation of Irs1 mRNA levels in the gastrocnemius muscle. Furthermore, L6 animals displayed lower whole-body lipid utilization than the L18 group, which could be related to the lower lipid intake and to the decreased mRNA levels of the fatty acid transporter gene Fatp1 observed in the soleus muscle. The profound differences observed between L6 and L18 rats could be related with hepatic and muscular changes in the expression of circadian rhythm-related genes Cry1, Bmal1, Per2 and Nr1d1. Although further research is needed to elucidate the pathophysiologic relevance of these findings, our study could contribute to emphasize the impact of the consumption of highly palatable and energy dense foods regularly consumed by humans on the physiological and metabolic adaptations that occur in response to seasonal variations of day length, especially in diseases associated with changes in food intake and preference such as obesity and seasonal affective disorder.
Keywords: photoperiod, Circannual rhythms, Cafeteria diet, metabolic syndrome, Feeding Behavior, Glucose homeostasis
Received: 13 Aug 2018;
Accepted: 30 Oct 2018.
Edited by:Ovidiu C. Baltatu, Anhembi Morumbi University - Laureate International Universities, Brazil
Reviewed by:Arcady A. Putilov, Humboldt-Universität zu Berlin, Germany
Alan Rosenwasser, University of Maine, France
Copyright: © 2018 Mariné-Casadó, Domenech-Coca, Del Bas, Bladé, Arola and Caimari. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Lluís Arola, Eurecat (Spain), Barcelona, Spain, firstname.lastname@example.org