Muscular Strength of Upper and Lower Limbs and Self-Esteem in Chilean SchoolChildren: Independent Associations with Body Composition Indicators.

The aim of this study was to analyze the relationship between muscular strength from upper and lower limbs with self-esteem among Chilean schoolchildren, drawing independent associations with body composition indicators. The sample consisted of 1078 schoolchildren. The muscular strength of the upper and lower limbs was evaluated using a digital dynamometer and long jump performance. The general strength index was calculated based on Z-score values. Rosenberg's test was used to determine the level of self-esteem of participants. Body fat and body mass index were employed as body composition indicators. Boys had significantly more upper and lower strength, and a general strength index higher than girls (11.7 vs. 10.6; 109.7 vs. 97.4; 0.19 vs. -0.24, respectively). For boys and girls combined, there were no significant associations between all muscular strength variables and self-esteem. In boys, upper and lower limb strength was positively associated with self-esteem. In girls, no association between muscular strength and self-esteem was found. In both sexes, the general strength index was not associated with self-esteem. Strategies and programs that promote mental health and muscular strength among schoolchildren, specifically in boys, are needed.

[Impact of front-of-pack labeling on food purchase pattern in Chile]. / Impacto de los mensajes frontales de advertencia en el patrón de compra de alimentos en Chile.

INTRODUCTION: Objective: to analyze the impact of front-of-pack warning labeling (FOP-L) on food purchase patterns in Chilean families with children under 14 years of age after the implementation of the Law on nutritional labeling in Chile. Methods: a cross-sectional study in 468 parents/tutors from 11 schools in Santiago. The questionnaire investigated FOP-L perception, food purchase patterns, and the influence of children on the selection of foods purchased by the family. Results: mostly mothers are responsible for household food purchases (62.0 %). Parents with a higher schooling level had a greater knowledge of the regulation (p < 0.05). In all, 66.3 % did not consider label information before the law was implemented. The FOP-L considered most important was "High in sugars" (18.0 %); 49.5 % stopped buying some foods due to the presence of a FOP-L; 75.0 % of parents reported that their children accompanied them at the supermarket. A lower probability of food purchase pattern change was observed in families that did not consider the FOP-L an important tool (OR: 5.85; p < 0.001), did not understand the meaning of the FOP-L (OR: 2.99; p = 0.020), had not the habit of reading nutritional labeling prior to law implementation (OR: 2.63; p < 0.001), or had a child who requested specific foods (OR: 2.91; p = 0.009). Conclusion: factors associated with buying food with FOP-L included: not considering their presence important, lack of understanding, not having the habit of reading labels on packaged foods prior to the Law, and having a child requesting food at the supermarket.

INTRODUCCIÓN: Objetivo: analizar el impacto de los mensajes frontales de advertencia (MFA) en los patrones de compra de alimentos de familias chilenas con menores de 14 años después de la ley que regula el etiquetado nutricional en Chile. Métodos: estudio transversal que entrevistó a 468 apoderados de 11 establecimientos educacionales de Santiago. La encuesta pesquisó la percepción de los apoderados con respecto a los MFA, los patrones de compra y la influencia de los hijos en la compra de los alimentos adquiridos por la familia. Resultados: la madre es principalmente la responsable de las compras de alimentos del hogar (62,0 %). Los apoderados con escolaridad más alta presentaron mayor conocimiento de la regulación (p < 0,05). El 66,3 % no consideraban la información presente en el rótulo antes de la ley. El MFA considerado más importante fue "Alto en azúcares" (18,0 %). El 49,5 % dejaron de comprar algún alimento debido a la presencia de MFA. El 75,0 % de los apoderados indicó que sus hijos los acompañan en el momento de la compra. Se observó una menor probabilidad de cambio en el patrón de compra de alimentos en las familias que no consideraban importante los MFA (OR: 5,85; p < 0,001), que no entendían los MFA (OR: 2,99; p = 0,020), que no tenían el hábito de leer el etiquetado antes de la ley (OR: 2,63; p < 0,001) y en las que el niño solicitaba algún alimento en el momento de la compra (OR: 2,91; p = 0,009). Conclusión: los factores asociados a la compra de alimentos con MFA fueron: no considerarlos importante, no entenderlos, no tener el hábito de leer el etiquetado y la solicitud de alimentos por los hijos en el momento de la compra.

Relative handgrip strength, nutritional status and abdominal obesity in Chilean adolescents.

Handgrip strength (HGS) is a well-established indicator of muscle strength and can help to identify risk of sarcopenic obesity in children. This study explores the relationship between adiposity and muscular strength in healthy Chilean adolescents. Adolescents (n = 491) aged 10-17 were selected from five schools in Santiago, Chile. HGS was determined by dynamometry. Anthropometry (weight, height, waist and mid arm circumference), physical activity and socioeconomic status were also measured. Relative HGS (RHGS) was calculated by dividing maximum HGS of the dominant hand by body-mass index (BMI) and low RHGS was categorized as <25th percentile by sex. Logistic regression was used to determine the relationship between two markers of adiposity (abdominal obesity category by waist circumference and nutritional status measured by BMI category) and low RHGS, adjusting for possible confounding variables. Participants were on average 13.6y (2.4), 32.8% were overweight or obese and 37.5% were at risk of or had abdominal obesity. RHGS was 1.25 kg/kg/m2 overall, with a significant difference by sex (1.51 for boys versus 1.14 for girls). In adjusted analyses, boys and girls with risk of abdominal obesity, had 3.3 (1.6-6.6) and 4.1 (1.8-9.3) increased odds of low RHGS, respectively, compared to boys and girls with normal waist circumference. Those with abdominal obesity compared to normal WC, had 8.5 (3.4-21.4) and 6.5 (2.0-21.3) increased odds of low RHGS for boys and girls, respectively. We observed similar associations for BMI category. In our sample of healthy adolescents, higher adiposity related to greater odds of low muscle strength measured by dynamometry. Considering the demographic shift from a young to an aging population in many countries, along with the increasing prevalence of obesity beginning in childhood, understanding how adiposity relates to low muscle strength is of growing importance.