Fernando Vio

Obesity trends and determinant factors in Latin America

Obesity rates have increased markedly in Latin America, especially during the last 10-15 years, becoming a public health problem in most countries. Prevalence of obesity among preschool children remains low, while among schoolchildren it has increased considerably. Prevalence is high in the adult population, especially among women with less schooling. In developed populations, obesity occurs more frequently among the poor; the opposite occurs in less developed societies, where in households undergoing nutritional transition, underweight can coexist with obesity. The most important determinant factors involved in the increasing obesity prevalence are fetal and infant nutritional conditions (stunting), education and socioeconomic conditions, dietary changes (especially increased total energy intake), and physical inactivity. Because chronic diseases are the main causes of death in the Region and obesity is one of the main risk factors for these diseases, policies to improve economic and educational levels with the implementation of health promotion and prevention should be a priority in every country.

School-based obesity prevention in Chilean primary school children: methodology and evaluation of a controlled study.

OBJECTIVE:To assess the impact of a 6 months nutrition education and physical activity intervention on primary school children through changes in adiposity and physical fitness.DESIGN: Longitudinal school-based controlled evaluation study.SUBJECTS: Children from 1st to 8th grade, 2141 in intervention and 945 in control schools.INTERVENTION: Nutrition education for children and parents, ‘healthier’ kiosks, 90 min of additional physical activity (PA) weekly, behavioral PA program and active recess.MEASUREMENTS: Adiposity indices (BMI, BMI Z-score, triceps skinfold thickness (TSF), waist circumference and physical fitness (20 m shuttle run test and lower back flexibility).RESULTS: Positive effect on adiposity indices (except TSF) was observed in boys (P<0.001 for BMI Z), while both physical fitness parameters increased significantly in both boys (P<0.001 for each test) and girls (P<0.0001 for each test). A differential effect in BMI Z was observed according to baseline nutritional status.CONCLUSIONS: This intervention showed a robust effect on physical fitness in both genders and decreased adiposity only in boys.

Trends in overweight and obesity prevalence in Chilean children: comparison of three definitions

Objective: To compare trends in prevalence of overweight and obesity among Chilean children using three different criteria.Methods: Descriptive cross-sectional school-based study to analyse these trends in 6-y-old boys and girls who entered first grade in 1987, 1990, 1993, 1996 and 2000. Gender-specific prevalence of overweight and obesity were determined with three criteria: weight for height (W-H) Z-scores compared to NCHS 1977; present reference used by the Ministry of Health; and body mass index (BMI) compared to the revised US CDC Growth Charts with cut-off values of P85-95 and P-95 and IOTF reference with cut-offs extrapolated from an adult BMI of 25 and 30.Results: The prevalence of overweight determined by W-H (WHO) increased from 15% in 1987 to 20% in 2000 for boys and from 17.2 to 21.8% for girls. With BMI-CDC, the increase was from 13.2 to 19.2% for boys and 12 to 18.5% for girls. With BMI-IOTF, rates were very similar. Prevalence of obesity using W-H (WHO) increased from 6.5% in 1987 to 17% in 2000 for boys and from 7.8 to 18.6% for girls. Using BMI-CDC, the increase was from 5.1 to 14.7% for boys and from 4 to 15.8% for girls; using BMI-IOTF prevalence estimates were much lower.Conclusions: Obesity prevalence in children has increased over time, and trends are similar independent of criteria. The reference used to define prevalence is important since it provides different estimates. Policy makers should be aware that a spurious drop in prevalence may appear if the IOTF reference is compared to the other criteria.

Nutritional status, food consumption and physical activity among Chilean school children: a descriptive study

Objective: To assess the nutritional status, food consumption and physical activity (PA) habits of Chilean school children, as a baseline for developing an educational intervention.Design: Cross-sectional study.Subjects: A total of 1701 children from 3rd to 7th grade in nine schools located in three geographical regions.Methods: We determined body mass index, food consumption (quantified FFQ which we categorised into five groups), PA in terms of TV viewing and frequency of after school PA. The data were analysed according to age, nutritional status and gender. A logistic regression analysis was performed using obesity as outcome.Results: Obesity was higher among boys; younger children presented higher prevalence in both genders. Daily intake of dairy products varied between 240 and 308 g, fruits/vegetables, between 197 and 271 g, energy-dense foods between 343 and 460 g. In all, 22.3 and 47% of the children watched over 3 h of TV during the week and weekend, respectively. Older children watched significantly more TV during the week, while on weekends all children increased this time significantly. Boys were more active than girls after school. The logistic regression analysis showed a significant association between obesity and low intake of dairy products.Conclusions: Prevalence of obesity among Chilean children is high. Although TV time, intake of energy dense foods and fruits/vegetables appeared as risk factors for obesity, only dairy consumption was significantly associated with obesity.Sponsorship: FAO

Epidemiological transition in Latin America: The case of Chile

To describe Chiles stage of epidemiological transition, a descriptive study of the changes to the demographic and economic profile of this country during the last 20 years is presented. The decline in the total fertility rate from 3.4 in 1970 to 2.6 in 1992 and the important decrease in general and infant mortality rate has led to an increase of life expectancy of 8 years for men and 9 years for women. This has resulted in changes to the age structure and causes of mortality and morbidity of the population. A reduction of 82% in the proportion of deaths among children < 1 year and a 73% increase of mortality amongst those 65 years and older can be observed. In line with these changes non-communicable diseases have increased from 53.7% of all deaths in 1970 to 74.9% in 1991. In the same period mortality rates from cardiovascular causes have decreased from 189.6 to 161.1 per 100,000 population, whilst their relative proportion of all causes has increased from 22.3% to 29%. High prevalence of risk factors should lead to a significant increase of chronic diseases in future years. Regarding morbidity, a high incidence rate for tuberculosis persists together with an increase of infections of the digestive system and of sexually transmitted diseases. A decrease in the rates of diseases preventable by immunisation has been noted. It is concluded that, as defined by population mortality statistics, Chile is in a post-transition stage but with a persistence of some infectious diseases corresponding to a transitional stage of development.

Two-year controlled effectiveness trial of a school-based intervention to prevent obesity in Chilean children

OBJECTIVE Obesity prevalence among Chilean children is 19.4%. The present study aimed to assess the effectiveness of a school-based obesity prevention programme. DESIGN Non-randomized controlled study. The intervention included activities in nutrition and physical activity, fully applied the first year and partially in the second one. Primary outcomes were BMI Z-score (BMIZ) and obesity prevalence; secondary outcomes were waist circumference and triceps skinfold thickness. Time effects were assessed by changes in BMI-related variables by gender and period (ANOVA and Tukey test), while intervention effects were determined by comparing changes in (i) obesity prevalence by gender and period (PROC GENMOD) and (ii) BMIZ according gender, age and period (PROC MIXED). SETTING Primary schools in the Chilean cities of Casablanca (intervention group) and Quillota (control group). SUBJECTS One thousand seven hundred and fifty-nine children from three schools (intervention group) and 671 from one school (control group). RESULTS Over the two years, obesity prevalence and BMIZ declined significantly in the intervention group; from 17.0% to 12.3% and 14.1% to 10.3% in boys and girls, respectively, and from 0.62 to 0.53 and 0.64 to 0.58, respectively. In the control group, obesity remained stable at about 21% and 15%, while BMIZ increased significantly in the second year. BMIZ declined in both genders and all age categories in the intervention group during the first year (significant only in younger boys). No changes occurred during the summer, while during the second year, BMIZ increased in boys and girls from both groups (significant only in the younger control boys). Obesity declined significantly only in boys during the first year. CONCLUSION Effectiveness was greater in the first school year and more evident in younger boys.

Promoción de salud y actividad física en Chile: política prioritaria

This piece describes and analyzes the situation with respect to physical activity in Chile and the policies and strategies that have been developed in order to combat sedentary lifestyles. The level of sedentary lifestyles in the Chilean population is very high, with 91% performing less than 30 minutes of physical activity three times per week. This predicament has worsened as a result of increased urbanization and economic growth over the past decade, with a resulting increase in the number of cars and televisions, along with a rise in the number of hours that workers are on the job each day. In order to deal with this situation a policy to develop physical activity was implemented as a part of the countrys general health promotion policy. This policy is overseen by the CHILE LIFE Council (Consejo VIDA CHILE), which is made up of 28 Chilean institutions. The policy encompasses various strategies, such as preparing guides to active living for the Chilean population, conducting educational activities and human resources training for kindergartens and other schools, establishing regulatory measures, performing research, carrying out media campaigns, reclaiming public spaces for recreation, and creating incentives for physical activity in the workplace. These strategies have been well received by the general population, academicians, professionals, and technicians. This makes it possible to foresee achieving in the medium and long term the objectives that have been set: more active lives and a better state of health for the Chilean population.

Estrategia de prevención de obesidad en escolares: Efecto de un programa aplicado a sus profesores (2007-2008)

Background: In 2007, a preventive strategy for childhood obesity, that included food education and an increase in physical activity, was implemented in seven public schools located in Santiago. In four of these schools, a counseling program about healthy lifestyles for teachers was also carried out. Aim: To test if counseling had an effect in the intervention for children. Material and Methods: Anthropometric measures were assessed in children at baseline and after two years of intervention. Teachers were also evaluated with anthropometry and a blood sample was obtained to measure blood glucose and serum lipids. Results: Four hundred twelve children from schools whose teachers had counseling and 237 children from schools whose teachers did not have it were evaluated. Twenty-eight teachers with and 19 with no counseling were assessed. In children, the overall prevalence of obesity decreased from 20.2 to 18.3% (p = 0.03). This reduction was only significant among females. BMIZ score decreased significantly in children of both genders. No effect of counseling was observed on weight reduction. Among teachers that received counseling, the prevalence of obesity decreased from 25 to 22.4%, with significant improvements in blood glucose and HDL cholesterol. Conclusions: Counseling directed at teachers did not improve the effect of a program to reduce obesity among schoolchildren.

Childhood nutrition in Chile: From deficit to excess

Abstract Chile has undergone an epidemiological and nutritional transition. In children, there has been an important decline in the rates of nutritional deficit, measured as weight/height (W/H) and height/age (H/A) with a corresponding increase in the prevalences of overweight and obesity. The purpose of this paper is to analyze these changes and present the results to the institutions in charge of large scale food programs to act accordingly with the current nutritional situation of their beneficiaries. This is a descriptive population-based study, which utilized the data collected by the nutritional information systems operating within the two programs with the widest coverage, the Complementary Feeding and the School Feeding Programs. The beneficiaries of the first one are infants and preshoolers, and although those of the second one are primary and secondary school children, the system only collects data on first graders. Results show that in terms of W/H, the percentage of undernourished children was already very low in 1985 and almost inexistent by 1995. With regard to growth retardation, 9.6% of children under 6 and 11% of children in first grade were stunted a decade ago. This proportion declined considerably, and is presently a problem only in 4.8% of first graders. Stunting in this group increases with age and was found to be more common among boys. With respect to nutritional excess, obesity rates have increased rapidly, 56% in children under 6. Among children in first grade, these prevalences are presently high and range from 11.1% to 14.3% according to age. This rapid change in nutrition, from deficit to excess, should be taken into account by policy makers not only to adjust the current nutrition programs but to promote a healthy lifestyle in other ambits.

Energy requirements in Chilean infants

AIM To evaluate the energy requirements of breast fed infants. METHODS The study was conducted in 17 healthy exclusively breast fed infants of normal birth weight (mean (SD) 3332 (280) g). Energy expenditure by the doubly labelled water method and milk intake by the dose to infant method were measured at 34 (4) days. A dose of 0.2 g/kg deuterium oxide (99.8%) and 2.0 g/kg 10% 18O labelled water was given to the infants, and urine samples were collected for seven consecutive days after dosing. RESULTS The mean (SD) weight of the infants during the period of evaluation was 4617 (343) g and weight gain 34.0 (7.5) g/day. Daily milk intake was 728 (101) g and its metabolisable energy content 2.71 kJ/g. The energy expenditure of the infants was 1205 (312) kJ/day and energy required for growth was 607 (130) kJ/day. When combined this produced an energy requirement of 391 kJ/kg/day for these infants. CONCLUSION These data agree with those from other studies in the United Kingdom and the United States and suggest that adequate growth can be achieved with 19.4% less energy than recommended by FAO/WHO/UNU.