Introduction: 

The aim of the present study was to evaluate the effect of high fat diet rich in lard or in fish oil on the development of obesity and on insulin resistance at the whole body level and at the skeletal muscle level.

Methods: 

Three groups of rats fed for 6 weeks with: standard diet (N), high fat diet rich in lard (40% J/J) (L), high fat diet rich in fish oil (40% J/J) (F) were used. Energy balance analysis and oral glucose tolerance were assessed. At skeletal muscle level, histological and immunohistochemical analyses, mitochondrial energy efficiency and measurement of insulin stimulated phosphorylation of protein kinase B (PKB/AKT) were performed.

Results: 

L rats showed an increased body weight, lipid gain, and total body energy efficiency and a reduced tolerance to oral glucose load compared to F rats. L rats showed: a) the widest glycogen depleted areas by PAS methods, b) the lightest immunostaining for adipocyte differentiation-related protein (ADRP), c) the lowest insulin-induced AKT-phosphorylation, d) the highest mitochondrial energy efficiency.

Conclusions: 

In chronic overnutrition, high fat diet rich in fish oil, compared to high fat diet rich in lard, induces a lower glucose dependent insulin secretion, as well as a lower adiposity by decreasing total body and muscle mitochondrial energy efficiency and by improving insulin resistance (as showed by Akt phosphorilation, glycogen content and ADPR).

Conflict of Interest: 

None disclosed

Funding:

No funding