Differential effects of saturated versus unsaturated dietary fatty acids on weight gain and myocellular lipid profiles in mice

Abstract

Objective:In conditions of continuous high-fat (HF) intake, the degree of saturation of the fatty acids (FAs) in the diet might have a crucial role in the onset of obesity and its metabolic complications. In particular, the FA composition of the diet might influence the storage form of lipids inside skeletal muscle. The aim of the present study was to examine whether the FA composition of HF diets differentially affects weight gain and accumulation of myocellular triacylglycerol (TAG) and diacylglycerol (DAG). Furthermore, we examined whether the FA composition of the diet was reflected in the composition of the myocellular lipid intermediates.Design:C57Bl6 mice were fed HF diets (45% energy) mainly containing palm oil (PO), cocoa butter (CB), olive oil (OO) or safflower oil (SO; n=6 per group) for 8 weeks. A low-fat diet (10% energy, PO) was used as control. Body weight was monitored weekly. At the end of the dietary intervention, myocellular TAG and DAG content and profiles were measured.Results:We here show that HF_CB prevented weight gain after 8 weeks of HF feeding. Furthermore, the HF diet rich in SO prevented the accumulation of both myocellular TAG and DAG. Interestingly, the FA composition of DAG and TAG in skeletal muscle was a reflection of the dietary FA composition.Conclusion:Already after a relatively short period, the dietary FA intake relates to the FA composition of the lipid metabolites in the muscle. A diet rich in polyunsaturated FAs seems to prevent myocellular lipid accumulation.

Long-chain SFA at thesn-1, 3 positions of TAG reduce body fat deposition in C57BL/6 mice

“…On the other hand, it was found that the different test oils had resulted in fat deposition to different extents in the subcutaneous and visceral tissues as well as total fat:feed (Table 3). Hence, the present study shows that body mass gain and fat deposition do not necessarily occur in tandem, and this clarifies the previous studies ( 1 , 8 ) , which used body mass gain as the marker for obesity. We, therefore, focused on normalisation data (Table 3), namely fat:feed, in the present evaluation of diet-induced adipogenic oils.…”

“…Generally, the intake of saturated fats has been perceived to exert deleterious effects on body fat deposition. Nonetheless, cocoa butter, a saturated fat, which has 63 g SFA/100 g total fatty acids, has been reported to prevent weight gain when compared with olive oil and safflower oil due to the presence of high amounts of palmitic and stearic acids ( 8 ) .…”

Stearic acids atsn-1, 3 positions of TAG are more efficient at limiting fat deposition than palmitic and oleic acids in C57BL/6 mice

“…The observation reported in previous literature ( 4 ) that COB is better at preventing fat accretion than palm oil has been successfully elucidated in the present study. Besides this, in our previous work ( 14 ) , we observed that dietary oil containing high amounts of linoleic and linolenic acids at sn -1, 3 positions, such as soyabean oil, led to significantly higher fat deposition than the diet enriched with palm olein.…”

“…Obesity is a cardiovascular risk factor that is also associated with a substantial increase in the risk of type 2 diabetes, hypertension and lipoprotein metabolism disorders. Concerted efforts have been made to establish the relationship between obesity and lipid intake; yet, most of the studies are merely based on the total SFA ( 1 – 4 ) , total unsaturated fatty acid ( 1 – 5 ) , MUFA ( 3 ) , n -6 PUFA ( 3 , 6 – 9 ) and n -3 PUFA ( 8 , 10 – 12 ) contents of edible oils. In general, a high-SFA-rich diet is perceived to be more obesogenic than diets with lower saturated contents ( 1 – 3 ) .…”

Animal models of obesity and diabetes mellitus

“…For example, in rats, dietary fats from an animal source, such as lard, have a more pronounced effect on adiposity and insulin resistance than vegetable fats 142 . Even subtle modifications, such as changes in the ratio of unsaturated to saturated fatty acids 143 and the physical form of the diet (liquid versus solid) 144,145 , lead to different DIO outcomes. For example, the fat source used for the preparation of HFDs is the critical element that determines whether germ-free mice are resistant or susceptible to DIO [146][147][148] .…”