Conjugated linoleic acid and phytosterols counteract obesity induced by high-fat diet

This study aims to evaluate the effects of dietary conjugated linoleic acid (CLA) and phytosterol supplementation and their combination added to high fat diet to verify their action on the satiety hormones, food intake, weight loss and peripheral glucose intolerance and insulin resistance in healthy rats. Twenty-one-day-old male healthy Sprague-Dawley rats were divided into five groups (n = 5): Standard group (P), Standard High-Fat group (HF), and three high-fat groups fed diets with 2% CLA added (HC), 2% phytosterol (HP) and 2% CLA plus 2% phytosterol (HS). The standard diet was AIN-93G with 12% protein and 4% vegetable oil; the high-fat diet contained 12% protein and 35% fat (4% vegetable oil and 31% animal fat). The experimental period lasted 8 weeks. The groups receiving supplements showed a significant reduction of retroperitoneal and epididymal adipose tissue as compared to the HF group (p < 0.05). However, there was no improvement in insulin resistance and glucose in either supplemented group (p < 0.05). The leptin decreased only in the groups that were receiving CLA (p < 0.05). All supplemented groups showed a reduction in diet consumption, but the groups that received the supplements showed weight reduction compared to the HF group (p <  0.05). The animals that received the supplements alone or in combination showed reduced fat mass and the effect was potentiated in the group HS, but there was no improvement in ghrelin, adiponectin insulin and glucose resistance. The supplements alone or in combination promoted reduction of food intake and also promoted weight loss in experimental animals.

► CLA showed an important effect in reduction of leptin in obesity induced by high fat diet. ► Phytosterol, more than CLA, have contributed on the reduction of retroperitoneal and epididymal adipose tissue. ► Phytosterol, more than CLA, played a role on the reduction of weight of the experimental animals. ► CLA and/or phytosterols led to a reduction in obesity.