ABSTRACT
Background
Development of obesity and its comorbidities is not only the result of excess energy intake, but also of dietary composition. Understanding how hypothalamic metabolic circuits interpret nutritional signals is fundamental to advance towards effective dietary interventions.
Objective
We aimed to determine the metabolic response to diets enriched in specific fatty acids.
Methods
Male mice received a diet enriched in unsaturated fatty acids (UOLF) or saturated fatty acids (SOLF) for 8 weeks.
Results
UOLF and SOLF mice gained more weight and adiposity, but with no difference between these two groups. Circulating leptin levels increased on both fatty acid-enriched diet, but were higher in UOLF mice, as were leptin mRNA levels in visceral adipose tissue. In contrast, serum non-esterified fatty acid levels only rose in SOLF mice. Hypothalamic mRNA levels of NPY decreased and of POMC increased in both UOLF and SOLF mice, but only SOLF mice showed signs of hypothalamic astrogliosis and affectation of central fatty acid metabolism. Exogenous leptin activated STAT3 in the hypothalamus of all groups, but the activation of AKT and mTOR and the decrease in AMPK activation in observed in controls and UOLF mice was not found in SOLF mice.
Conclusions
Diets rich in fatty acids increase body weight and adiposity even if energy intake is not increased, while increased intake of saturated and unsaturated fatty acids differentially modify metabolic parameters that could underlie more long-term comorbidities. Thus, more understanding of how specific nutrients affect metabolism, weight gain, and obesity associated complications is necessary.
Acknowledgements
We would like to thank Maria Jimenez and Sandra Canelles for their excellent technical support.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Data availability statement
All data are available upon request.
Additional information
Funding
Notes on contributors
Jesús Fernández-Felipe
Jesús Fernández-Felipe is a doctoral student in the Faculty of Pharmacy, Universidad San Pablo-CEU, Madrid.
Maria Valencia-Avezuela
Maria Valencia-Avezuela is now a doctoral student in the Instituto de Investigaciones Científicas Alberto Sols, CSIC, Madrid. This work was part of her Master’s Thesis at the Hospital Infantil Universitario Niño Jesús.
Beatriz Merino
Beatriz Merino is professor in the Faculty of Pharmacy, Universidad San Pablo-CEU, Madrid.
Beatriz Somoza
Beatriz Somoza is professor in the Faculty of Pharmacy, Universidad San Pablo-CEU, Madrid.
Victoria Cano
Victoria Cano is professor in the Faculty of Pharmacy, Universidad San Pablo-CEU, Madrid.
Ana B. Sanz-Martos
Ana B. Sanz-Martos is a doctoral student in the Faculty of Pharmacy, Universidad San Pablo-CEU, Madrid.
Laura M. Frago
Laura M. Frago is professor at the Faculty of Medicine, Universidad Autónoma de Madrid.
Maria S. Fernández-Alfonso
Maria S. Fernández-Alfonso is full professor in the Department of Pharmacy at the Universidad Complutense, Madrid.
Mariano Ruiz-Gayo
Mariano Ruiz-Gayo is full professor at the Faculty of Pharmacy, Universidad San Pablo-CEU, Madrid.
Julie A. Chowen
Julie A. Chowen is Senior Researcher at the Hospital Infantil Universitario Niño Jesús, Madrid.