Consumption of branched-chain amino acids is inversely associated with central obesity and cardiometabolic features in a population of Brazilian middle-aged men: Potential role of leucine intake

To assess the potential associations of branched-chain amino acids (BCAA) consumption with central obesity (CObesity) and cardiometabolic risk factors in a population of Brazilian middle-aged men. Special attention was given to leucine intake. Cross-sectional study. Universidade Federal de Viçosa, Viçosa, Brazil. Two-hundred ninety-six middle-aged men (Age: 50.5 ± 5.0 years; Body mass index: 25.8 ± 3.5 kg/m2). Anthropometry, lifestyle features, blood biochemical parameters were assessed and dietary intake was estimated by a food frequency questionnaire. Participants were classified by the occurrence of CObesity, hypertriglyceridemia (HTG), hypertriglyceridemic waist phenotype (HWP) and metabolic syndrome (MetS). Subjects in the BCAA highest tertile (≥0.17 g/kg/d) presented lower occurrence of CObesity (36.0% vs 72.4%, P<0.01, z=−5.10), HTG (17.0% vs 30.6% P<0.032, z=−2.32), HWP (23.0% vs 46.9%, P<0.01, z=−3.57) and MetS (19.0% vs 34.7%, P<0.01, z=−2.57). They also exhibited lower values for Castelli index (total cholesterol:HDL-c) and triglycerides: HDL-c ratio than those in the first tertile, regardless of interfering factors (i.e. habitual physical activity, work position, smoking habit, and energy intake). Interestingly, leucine consumption showed similar associations with cardiometabolic risk factors, as compared to BCAA consumption (P<0.05). BCAA consumption was cross-sectionally and negatively associated with relevant cardiometabolic risk factors in a population of Brazilian middle-aged men. The content of leucine in BCAA consumption may have contributed to such relationship

Efeito do índice glicêmico no gasto energético e utilização de substrato energético antes e depois de exercício cicloergométrico Effect of glycemic index on energy expenditure and energy substrate utilization before and after exercise on a stationary bicycle

OBJETIVO: No presente artigo, avaliou-se o efeito do consumo, durante cinco dias consecutivos, de refeições diferindo em índice glicêmico no gasto energético, na oxidação de substrato energético e no consumo excessivo de oxigênio após o exercício. MÉTODOS: Participaram do estudo 15 homens bem treinados, com idade de M=24,4, DP=3,70 anos e consumo máximo de oxigênio (VO2max) de M=70,00, DP=5,32mL (kg.min)-1. Após o consumo das refeições, os participantes permaneceram por noventa minutos no calorímetro indireto Deltatrac®, para a avaliação dos parâmetros metabólicos. A seguir, foi realizado um exercício de 85 a 95% da frequência cardíaca máxima, em três estágios de dez minutos. Os parâmetros metabólicos foram novamente avaliados durante os sessenta minutos pós-exercício. RESULTADOS: Os tratamentos aplicados no estudo não afetaram o gasto energético, o consumo excessivo de oxigênio e a oxidação lipídica após o exercício. Entretanto, a taxa de oxidação de gordura foi maior durante os noventa minutos no grupo que consumiu a refeição de alto índice glicêmico antes do exercício, em relação ao da refeição de baixo índice glicêmico. Além disso, a taxa de oxidação lipídica do período pós-prandial foi inferior àquela obtida no período pós-exercício. CONCLUSÃO: Os resultados sugerem que enquanto o consumo de refeições de baixo índice glicêmico pode não exercer efeito benéfico, a realização de exercício físico pode promover maior oxidação lipídica e consequentemente afetar a redução do teor de gordura corporal.<br>OBJECTIVE: The present study assessed, on 5 consecutive days, the effect of consuming meals with different glycemic indices on energy expenditure, energy substrate oxidation and excessive oxygen consumption after exercise. METHODS: A total of 15 well trained men aged M=24.4, SD=3.70 years with a mean body mass index of M=21.97, SD=1.46 kg/m² and maximum oxygen uptake (VO2max) of M=70.00, SD= 5.32 mL(kg.min)-1 participated in the study. After the meal, the participants remained 90 minutes in the indirect calorimeter Deltatrac® for assessment of the metabolic parameters. Next, they exercised at 85-95% of their maximum heart rate in three bouts of 10 minutes. The metabolic parameters were reassessed within the 60 minutes following the exercise. RESULTS: The study treatments did not affect energy expenditure, excessive oxygen consumption or fat oxidation after exercise. However, the rate of fat oxidation in the 90 minutes that followed the meal was higher in those who consumed the high-glycemic index meal than in those who consumed the low-glycemic index meal. Moreover, the postprandial fat oxidation rate was lower than that observed after the exercise. CONCLUSION: These results suggest that, while the consumption of low-glycemic index meals may not have beneficial effects, exercise can promote greater fat oxidation and, consequently, reduce body fat