High-fat diet action on adiposity, inflammation, and insulin sensitivity depends on the control low-fat diet
Résumé
Animal studies using a high-fat diet (HFD) have studied the effects of lipid overconsumption by comparing a defined HFD either with a natural-ingredient chow diet or with a defined low-fat diet (LFD), despite the dramatic differences between these control diets. We hypothesized that these differences in the control diet could modify the conclusions regarding the effects that an increase of fat in the diet has on several metabolic parameters. For 11 weeks, C57bl6/J mice were fed a low-fat chow diet (8% energy from fat), a typical semisynthetic LFD (12%), or a semisynthetic HFD (sy-HF) (40%). Conclusions about the effect of sy-HF on body weight gain, subcutaneous adipose tissue, insulin sensitivity, and adipose tissue inflammation were modified according to the control LFD. Conversely, conclusions about epididymal and retroperitoneal adipose tissue; fat intake effects on liver and muscular lipids, cholesterol, free fatty acids, and markers of low-grade inflammation; and of adipose tissue macrophage infiltration were the same regardless of the use of low-fat chow diet or semisynthetic LFD. For some physiological outcomes, conflicting conclusions were even reached about the effects of increased fat intake according to the chosen low-fat control. Some deleterious effects of sy-HF may not be explained by lipid overconsumption but rather by the overall quality of ingredients in a semisynthetic diet. According to the control LFD chosen, conclusions on the lipid-related effects of HFDs must be formulated with great care because some end points are profoundly affected by the ingredient composition of the diet rather than by fat content.
Mots clés
AUC
Adipose tissue
BAT
CD11c
CD68
HFD
High fat diet
IL-6
Inflammation
Insulin sensitivity
LFD
MCP1
Mice
TG
WAT
area under the curve
brown adipose tissue
ch-LFD
chow LFD
cluster of differentiation 11c
cluster of differentiation 68
eWAT
epididymal white adipose tissue
high-fat diet
interleukin 6
low-fat diet
mRNA
messenger RNA
monocyte chemoattractant protein 1
pAKT
phosphorylated AKT
rWAT
retroperitoneal white adipose tissue
scWAT
semisynthetic high-fat diet
semisynthetic low-fat diet
subcutaneous white adipose tissue
sy-HFD
sy-LFD
triglycerides
white adipose tissue