Food advertising and television exposure: influence on eating behavior and nutritional status of children and adolescents

This study aimed to evaluate the influence of food advertising and television exposure on eating behaviour and nutritional status of children and adolescents. It was a cross sectional study developed among 116 students from a private school in Brazil. Socio-demographic and health conditions were evaluated. Anthropometric data, food consumption, physical activity, television viewing habits and behaviour in relation to food advertising were also investigated. Among the results, a 1:2 relationship was identified between the number of televisions and residents per household. Excessive weight was present in 25.8% of subjects and 66.4% of children watched television while eating. Children were exposed to television for a median of 3.0 hours daily (95% CI: 2.9 to 3.6). There was a direct association between attraction to foods advertised and purchasing the product (p<0.001) and a positive relationship between the number of televisions per household and body weight (r=0.246, p=0.015) and the amount of liquid consumed during meals (r=0.277, p=0.013). Findings also highlighted the association between watching television while eating and the reduced probability of fruit consumption (p=0.032), contrasted with a greater likelihood of daily artificial juice intake (p=0.039). In conclusion, watching television is associated with lower probability of daily consumption of fruits and the number of television at household is positively related to BMI in children and adolescents.

Publicidad de los alimentos y la exposición a la televisión: Influencia sobre la conducta alimentaria y el estado nutricional de los niños y adolescentes. El estudio objetivó evaluar la influencia de la publicidad de alimentos y la exposición a la televisión en la conducta alimentaria y estado nutricional de niños y adolescentes. El estudio es transversal con 116 estudiantes de una escuela privada en Brasil. Información sociodemográfica y de la condición de salud fueron evaluadas. Antropometria, el consumo de alimentos, practica de actividad física, hábitos de ver la televisión y el comportamiento en relación con la publicidad de alimentos también fueron investigados. Entre los resultados, una relación de 1:2 fue identificada entre el número de televisores por hogar y los residentes. El exceso de peso estaba presente en 25,8% de los sujetos y 66,4% de ellos veían la televisión mientras comían las refecciones. Los niños fueron expuestos a la televisión por un promedio de 3,0 horas al día (95% IC: 2,9-3,6). Se observó una asociación directa entre la atracción de los alimentos anunciados y la compra del producto (p<0,001) y una relación positiva entre el número de televisores por hogar y el peso corporal (r=0,246; p=0,015) y la cantidad de liquido consumido durante las refecciones (r=0,277; p=0,013). Los resultados presentó la asociación entre ver la televisión mientras se alimenta y la probabilidad de reducción del consumo de frutas (p=0,032), en contraste con una mayor probabilidad de consumo de jugo artificial (p=0,039). En conclusión, ver la televisión en demasiado se asocia con una menor probabilidad de consumo diario de frutas y el numero de televisores en el hogar se relaciona positivamente con el índice de masa corporal.

Relationship between calcium intake and body mass index in adolescents

Epidemiologic and experimental data support the possibility that dietary calcium intake plays a role in human body weight regulation. The aim of the present study was to evaluate calcium intake and its relationship with body mass index (BMI) in adolescents. Weight, height, 3-day food record and a food frequency questionnaire were collected among all adolescents participants at the Outpatient Clinic for Adolescents at the Federal University of Sao Paulo between 2001 and 2003. The statistical analysis comprised Chi-square, Student's T-test, Pearson correlation and linear regression. One-hundred and twenty-one adolescents were studied (62.8 per cent female), with a mean age of 14.9 ±2.2 years old. Mean energy and calcium intakes were 1729.9±557.8 kcal/day and 598.2±287.9 mg/day respectively, with no significant statistical differences between sex or age. Almost ninety-eight percent of adolescents presented a mean calcium intake lower than proposed values. Calcium intake adjusted for energy presented a significant negative correlation with body weight (r=-0.194, p=0.03) and BMI (r=-0.185, p=0.04). Furthermore, adolescents in the lowest quartile of calcium intake presented higher BMI (29.7±7.4 kg/m2) than adolescents in the highest calcium quartile. These results indicated a dietary calcium intake lower than recommendations for this life stage, and a contribution of this mineral in the body mass index