OBJECTIVES: Dietary omega-3 fatty acids have been efficacious in decreasing serum cholesterol levels and reducing the risk of cardiovascular disease. However, the metabolic and molecular changes induced by the omega-3 fatty acid α-linolenic acid (ALA), which is found in linseed oil, are not fully understood. In this study, we showed a correlation between ALA and insulin resistance, inflammation and endoplasmic reticulum stress (ERS). METHODS: We studied 40 male mice (C57/BL6) divided into 4 groups: a control (C) group, a control + omega-3/ALA (CA) group, a high-fat diet (HFD) (H) group and a high-fat diet + omega-3/ALA (HA) group. For 8 weeks, the animals in the H and HA groups were fed a high-fat (60%) diet, while the animals in the C and CA groups received regular chow. The diets of the CA and HA groups were supplemented with 10% lyophilized ALA. RESULTS: ALA supplementation improved glucose tolerance and reduced insulin resistance, as measured by intraperitoneal glucose tolerance tests and the homeostasis model assessment for insulin resistance, respectively. In addition, ALA reduced hepatic steatosis and modified the standard fat concentration in the liver of animals fed an HFD. Dietary ALA supplementation reduced the serum levels of interleukin 6 (IL-6), interleukin 1 beta (IL-1β) and monocyte chemoattractant protein-1 (MCP-1), increased the expression of important chaperones such as binding immunoglobulin protein (BIP) and heat shock protein 70 (HSP70) and reduced the expression of C/EBP-homologous protein (CHOP) and X-box binding protein 1 (XBP1) in hepatic tissues, suggesting an ERS adaptation in response to ALA supplementation. CONCLUSIONS: Dietary ALA supplementation is effective in preventing hepatic steatosis; is associated with a reduction in insulin resistance, inflammation and ERS; and represents an alternative for improving liver function and obtaining metabolic benefits.

OBJETIVO: comparar os índices de adiposidade em indivíduos praticantes de atividade física para avaliar o comportamento, a capacidade diagnóstica e determinar qual parâmetro melhor reflete e diagnostica a adiposidade corporal. MÉTODOS: Um estudo transversal foi realizado em 100 indivíduos fisicamente ativos (59% mulheres). Os participantes foram submetidos à avaliação antropométrica e de composição corporal, sendo aferidos peso, estatura, circunferências, pressão arterial e análise de impedância bioelétrica. Foi aplicado um questionário de atividade física (IPAQ, versão curta), além de um questionário sobre o possível uso da suplementação nutricional. Os dados foram analisados estatisticamente, com nível de significância estabelecido em p <0,05. RESULTADOS: as médias de idade, estatura, peso e IMC foram 24,2 ± 6,65 anos, 169,5 ± 8,94 cm, 69,1 ± 14,83 kg e 23,9 ± 4,19 kg/m2, respectivamente, com diferença significativa entre os gêneros, exceto para idade. A maioria dos sujeitos estava na faixa de peso normal, com um IMC de 18,5 a 24,9 kg/m2, e eram muito ativos. O BMIfat foi melhor correlacionado com a gordura corporal para homens (r = 0,896) e mulheres (r = 0,935), seguido pelo IMC (0,689 e 0,767, respectivamente) e BAI (0,590 e 0,718). CONCLUSÕES: Os índices de adiposidade são alternativas viáveis para o diagnóstico da obesidade e devem ser mais explorados como medidas rápidas, práticas e de baixo custo na prática clínica.

OBJECTIVE: To compare adiposity indexes in physical activity individuals to evaluate behavior, diagnostic ability and to determine which parameter best reflects and diagnoses body fatness. METHODS: A cross-sectional study was performed on 100 physically active individuals (59% female). The participants were submitted to anthropometric and body composition evaluation; we measured weight, height, circumferences, blood pressure and bioelectrical impedance analysis. A physical activity questionnaire (IPAQ, short version) was applied, as well as a questionnaire about the possible use of nutritional supplementation. The data were statistically analyzed, with significance level set at p <0.05. RESULTS: Mean age, height, weight and BMI were 24.2 ± 6.65 years, 169.5 ± 8.94 cm, 69.1 ± 14.83 kg and 23.9 ± 4.19 kg/m2, respectively, with a significant difference between the genders, except for age. Most of the subjects were in the normal weight range, with a BMI of 18.5 to 24.9 kg/m2, and were very active. BMIfat correlated better with body fat for males (r = 0.896) and females (r = 0.935), followed by BMI (0.689 and 0.767, respectively) and BAI (0.590 and 0.718). CONCLUSIONS: Adiposity indexes are viable alternatives for the diagnosis of obesity and should be more explored as fast, practical and low cost measures in clinical practice.