Effect of High Fat Diets on Body Mass, Oleylethanolamide Plasma Levels and Oxytocin Expression in Growing Rats

Obesity prevalence in developed countries has promoted the need to identify the mechanisms involved in control of feeding and energy balance. We have tested the hypothesis that different fats present in diet composition may contribute in body weight gain and body indexes by regulation of oxytocin gene (oxt) expression in hypothalamus and Oleylethanolamide (OEA) levels in plasma. Sprague–Dawley rats were fed two high fat diets, based on corn (HCO) and extra virgin olive oil (HOO) and results were compared to a low fat diet (LF). LC‐MS/MS analysis showed an increasing trend of OEA plasma levels in HOO group, although no significant differences were found. However, body weight gain of LF and HOO were similar and significantly lower than HCO. HCO rats also had higher Lee index than HOO. Rats fed HOO diet showed higher levels of hypothalamic oxt mRNA expression, which could indicate that oxytocin may be modulated by dietary lipids. Practical Applications After consumption of high fat diets, weight gain can be influenced and thereby controlled by the kind of lipids consumed. Results obtained suggest that oxytocin have an important role in body mass regulation and its expression could be increased by dietary olive oil. Althougth mechanism remains still unknow olive oil consumption could contribute to a higher wheigh loss than corn oil. So, olive oil‐based diets can be useful tools in weight loss programmes.