Genistein stimulates fatty acid oxidation in a leptin receptor-independent manner through the JAK2-mediated phosphorylation and activation of AMPK in skeletal muscle.

Obesity is a public health problem that contributes to the development of insulin resistance, which is associated with an excessive accumulation of lipids in skeletal muscle tissue. There is evidence that soy protein can decrease the ectopic accumulation of lipids and improves insulin sensitivity; however, it is unknown whether soy isoflavones, particularly genistein, can stimulate fatty acid oxidation in the skeletal muscle. Thus, we studied the mechanism by which genistein stimulates fatty acid oxidation in the skeletal muscle. We showed that genistein induced the expression of genes of fatty acid oxidation in the skeletal muscle of Zucker fa/fa rats and in leptin receptor (ObR)-silenced C2C12 myotubes through AMPK phosphorylation. Furthermore, the genistein-mediated AMPK phosphorylation occurred via JAK2, which was possibly activated through a mechanism that involved cAMP. Additionally, the genistein-mediated induction of fatty acid oxidation genes involved PGC1α and PPARδ. As a result, we observed that genistein increased fatty acid oxidation in both the control and silenced C2C12 myotubes, as well as a decrease in the RER in mice, suggesting that genistein can be used in strategies to decrease lipid accumulation in the skeletal muscle.

When clean eating isn't as faultless: the dangerous obsession with healthy eating and the relationship between Orthorexia nervosa and eating disorders in Mexican University students.

BACKGROUND: Orthorexia Nervosa is an eating disorder that has been scarcely studied in characteristics, causes and symptoms, as well as in consequences and the relationship with other eating disorders. The present study had as its main objective the analysis of said relationship and inquisition of the possibility of predicting the development of an eating disorder from the presence of orthorexia nervosa. Also, it analyzed the differences by sex in Mexican university students. METHODS: The sample consisted of 911 university students (65.4% women and 34.6% men), between an age range of 18 to 28 years old (M = 21 and SD = 1.9). Two questionnaires were responded: the ORTO14MX, a version of the ORTO-15 instrument previously validated in Mexican students, and the EDE-Q in its short version. Besides, sociodemographic data of interest was obtained and used for this study. RESULTS: The Pearson's correlation analysis demonstrated statistically significant relations, from mild to moderate, between the factors that make up both scales, while the linear regression analysis demonstrated that 40% of the variance is explained with the factors from the ORTO-14MX scale in the overall sample for the study. Additionally, statistically significant differences were found between men and women regarding all the subscales conforming the instruments that measured orthorexia and eating disorders. CONCLUSION: These results show a moderate predictive degree, that as promising as it is, isn't conclusive. Likewise, it was confirmed that women are still more vulnerable to develop orthorexia or another eating disorder. It can be concluded that there's a vast necessity for more studies measuring the relationship between orthorexia nervosa and eating disorders, in Latinamerican samples with diverse characteristics in sociocultural backgrounds, and clinical samples.

INTRODUCCIÓN: La ortorexia nervosa es un trastorno de la conducta alimentaria que ha sido poco estudiado, tanto en sus características, causas y síntomas, como en sus consecuencias y en la relación con otros trastornos de la conducta alimentaria. El presente estudio tuvo como objetivo analizar dicha relación e indagar si es posible predecir la aparición de un trastorno de la conducta alimentaria a partir de la presencia de ortorexia nervosa, además de analizar diferencias por sexo en estudiantes universitarios mexicanos. MÉTODO: Participaron en el estudio 911 estudiantes universitarios (65.4% fueron mujeres y el 34.6% hombres), en un rango de edades entre 18 y 28 años (M = 21 y DE = 1.9) que respondieron dos cuestionarios que son: ORTO-14MX, una versión del instrumento ORTO-15 previamente validada en estudiantes mexicanos y el EDE-Q en su versión corta, además de proporcionar algunos datos sociodemográficos de interés para este estudio. RESULTADOS: El análisis de correlación de Pearson reveló relaciones estadísticas significativas de leves a moderadas entre los factores que componen ambas escalas, mientras que el análisis de regresión lineal mostró un que un 40% de la varianza es explicada a partir de los factores que componen la escala ORTO-14MX en la muestra de estudio. Adicionalmente se encontraron diferencias estadísticamente significativas entre hombres y mujeres con respecto a todas las subescalas de los instrumentos que midieron ortorexia y trastornos de la conducta alimentaria. CONCLUSIONES: Estos resultados mostraron un grado de predicción moderada que sí bien es prometedora, no resulta totalmente concluyente. Asimismo, se confirmó que las mujeres siguen siendo más vulnerables a padecer ortorexia o un TCA. Se concluye la necesidad de continuar estudiando la relación entre la ortorexia y los TCAs, en muestras latinoamericanas con otras características socio demográficas y en población clínica.