Several studies show evidence that supplementation with leucine favors reducing body fat in animals submitted to various experimental conditions, including food restriction and high fat diet. However, the effect of supplementation with leucine associated with exercise in animals submitted to high-fat diet remains poorly informed, as well, the effects of these interventions on reversion of the deleterious effects on metabolism of glucose caused by the high fat diet.
PURPOSE: To evaluate the effect of supplementation with leucine associated with exercise in body fat and in the metabolism of glucose in rats previously submitted to high-fat diet.
METHODS: Initially thirty Sprague-Dawley rats were fed with high-fat diet for 15 weeks. Subsequently, they were distributed into control group (CG) (n = 7), leucine group (LG) (n = 8), exercise group (EG) (n = 8) and group exercise + leucine (GEL) (n = GEL 7). CG and EG were fed with AIN-93M diet, and LG and GEL were supplemented with 5% of leucine. EG and GEL were exposed to 60 minutes per day of swimming exercise for 6 weeks. After 21 weeks the animals were sacrificed and samples for analysis were collected. Two-way ANOVA was performed for statistical analysis with p<0.05.
RESULTS: When compared the factors exercised vs. sedentary and leucine vs. control, there was a significant difference in the sum of deposits of visceral fat (p<0.022 and p<0.034, respectively). The same results were observed between LG vs. CG (6.01 ± 1.18 vs. 7.79 ± 2.18 p<0.026) and GEL vs. LG (6.14 ± 0.78 vs. 7.79 ± 2.18, p<0.019). Significant differences were found among the factors exercised vs. sedentary (p<0.011) and leucine vs. control (p<0.047) for the morphometry of adipose tissue. The same was observed between the CG vs. LG (288.05 ± 53.54 vs. 380.26 ± 120.02, p<0.029) and GEL vs. LG (269.49 ± 36.70 vs. 380.26 ± 120.02, p<0.010). On the other hand there was no significant difference in insulin and HOMA index.
CONCLUSIONS: The results of this study suggest that supplementation with leucine does not reduce body fat nor the volume of adipocytes. Moreover, the effects of the association between leucine and exercise are attributed primarily to the exercise.
Supported by FAPESP, 07/59291-3 and 07/51964-9.