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Several epidemiological studies have related an increase of lipids in the postprandial state to an individual risk for the development of CVD, possibly due to the increased plasma levels of TAG and fatty acids (FA) through enzymes of FA metabolism. The interaction between nutrition and the human genome determines gene expression and metabolic response. The aim of the present study was to evaluate the influence of a fat overload on the gene mRNA levels of lipogenic regulators in peripheral blood mononuclear cells (PBMC) from patients with the metabolic syndrome. The study included twenty-one patients with criteria for the metabolic syndrome who underwent a fat overload. Measurements were made before and after the fat overload of anthropometric and biochemical variables and also the gene mRNA levels of lipogenic factors. The main results were that the fat overload led to an increased mRNA levels of sterol regulatory element binding protein-1 (SREBP1), retinoid X receptor α (RXRα) and liver X receptor α (LXRα) in PBMC, and this increase was associated with the FA synthase (FASN) mRNA levels. We also found that TAG levels correlated with FASN mRNA levels. In addition, there was a positive correlation of SREBP1 with RXRα and of LXRα with the plasma lipoperoxide concentration. The fat overload led to an increase in regulators of lipogenesis in PBMC from patients with the metabolic syndrome.

The aim of the present experiment was to test the hypothesis that during refeeding a redistribution of intra-abdominal fat takes place and that both the recovery of weight and the redistribution of intra-abdominal fat are related to the type of dietary fat. The experimental study was carried out using male Sprague-Dawley rats. Three groups of animals were fed diets with three different fatty acid profiles. Each group contained two branches, one fed normally and the other fed initially with a 50 % energy reduction followed by refeeding ad libitum with the same isoenergetic diet as the control branch, giving a total of six treatments. Measurements were made of the final and incremental weight of the rat, weight of the intra-abdominal adipose tissue (total intra-abdominal, epididymal, omental and retroperitoneal adipose tissue weight), and feed efficacy (weight increment/metabolizable energy intake). Carcass, epididymal, omental, and muscle lipid contents, carcass protein and energy density were also measured. The results revealed that diets rich in fish oil or olive oil increase catch-up growth more than diets rich in saturated fats. During refeeding the lipid content in the adipose tissue increases while that of muscle tissue decreases. A diet rich in saturated fats induces a relative increase in the amount of intra-abdominal adipose tissue. The lipid content in adipose and muscle tissues and the distribution of intra-abdominal fat can all be modified by the type of dietary fat.