Résumé
Abstract only The incidence of obesity, type 2 diabetes and cardiovascular disease in children is increasing and is exacerbated by a “western” diet. We examined the effect of short term consumption of high fat and/or sugar diets on cardiovascular risk factors in young male rats that received control (CON; 12% kcal fat/19% protein/69% carbohydrate), western (WES; 40/15/45%) or high fat (HF; 60/19/21%) diets for 2 weeks. Insulin sensitivity was lower in WES (34%) and HF (68%) than CON while blood glucose remained similar. Serum cholesterol and triglyceride levels were elevated in HF (43%) and WES (40%) respectively as was plasma xanthine oxidase activity (HF: P<0.05; WES: P=0.059) compared to CON; however there were no differences in blood levels of the lipid peroxidation product 4‐hydroxynonenal bound to proteins. Despite a lower left ventricular (LV) weight (P<0.05) and a trend towards higher collagen content in WES (P=0.053), there were no differences in LV morphology or function. Arterial stiffness tended to be higher in both WES (−5 ± 3%; P=0.081) and HF (−5 ± 2%; P=0.097) compared to CON (−12 ± 1%) with no differences in mean arterial pressure. LV mitochondrial Krebs cycle enzyme activities (citrate synthase, aconitase) were depressed in both groups. These data highlight early changes in some cardiovascular risk factors after short‐term consumption of diets high in fat and/or sugar in young animals prior to the onset of obesity.