[Carbohydrate and lipid consumption before a training session changed the fat mass in health-physically active adults: a controlled and randomized clinical trial].

INTRODUCTION: The effect of exercise on fat-acid oxidation depends on its intensity and duration. Pre-training ingest of carbohydrates (CH) decreases the rate of fat oxidation. In contrast, the effect of pre-consumption of monounsaturated fatty acids (MUFA) is less known. OBJECTIVE: the aim of this study was to compare the effect of pre-consumption of two isocaloric snacks in a standardized exercise session during a period of nine weeks and to quantify their impact in the fat oxidation and decrease of fat mass in healthy and physically active adults. METHODS: randomized, placebo-control clinical trial study. A total of 19 subjects between 20 and 39 years old were randomly distributed in three groups: CH group, with snack of high content of complex CH; FAT group, with snack of high content of MUFA; and control group, with a minimum fast for three hours before the training session. The measurements were rate of fat oxidation, body composition, and endurance training with continuing and intervallic modalities. RESULTS: the control group showed a tendency to fat mass decrease at the end of the intervention. The fat oxidation of group had a higher tendency than the CH and control group, before and after the intervention. Nevertheless, statistical differences of fat oxidation were not found between the groups. CONCLUSIONS: the fat oxidation and the decrease of fat mass may not be influenced by the type of food previously consumed before exercise.