Influence of a conventional or chemically defined normocaloric diet on metabolic and oxidative stress outcomes in an experimental rat model

The use of animal models is also fundamental to the comprehensive investigation of the mechanisms of diseases and comorbidities affecting humans. Selecting the appropriate control diet is essential for establishing the model and conducting the experiment effectively. The choice of diet for the control group is essential for conducting a high-quality experiment. Many studies have used chemically defined normocaloric diets (AIN-93); however, there are reports that these diets are associated with adverse metabolic effects that compromise the research. This study aimed to compare the effects of the AIN-93 diet with those of a conventional normocaloric diet on various metabolic, hormonal, and oxidative stress markers. Nineteen male Wistar rats were divided into two groups: conventional normocaloric diet (C) and chemically defined normocaloric diet (AIN-93G), for 30 weeks. After fasting, the animals were euthanized for analysis. Body composition, nutritional, systolic blood pressure, hormonal, biochemical, and oxidative stress parameters were analyzed and assessed using Student’s t-test, with p < 0.05 considered significant. The AIN-93G group showed higher levels of all fat deposits, final body weight, adiposity index, total cholesterol, insulin resistance, leptin, systolic blood pressure, feed efficiency, and oxidative stress markers compared to the C group. The results demonstrate that the AIN-93G diet promotes a less stable metabolic and redox profile compared with the conventional normocaloric diet.