Anthropometric indicators as predictors of total body fat and cardiometabolic risk factors in Chilean children at 4, 7 and 10 years of age.

BACKGROUND/OBJECTIVE: To compare the association between anthropometric indicators of global and central obesity as predictors of total body fat (TBF) and cardiometabolic risk factors in children. SUBJECTS/METHODS: A total of 1044 children were evaluated at 4 years (n=320), 7 years (n=1044) and 10 years (n=483). The following anthropometric indices were determined: body mass index (BMI) for age (BAZ, WHO), waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR). To estimate TBF we used validated predictive equations. We measured blood sample concentrations of glucose, insulin, triglycerides, total cholesterol, Low-density lipoprotein (LDL) and High-density lipoprotein (HDL), adiponectin, C-reactive protein (CRP) and Insulin-like growth factor-1 (IGF-1). RESULTS: Adiposity and cardiometabolic markers, particularly those related to glucose metabolism increased from 4 years to 10 years. BAZ and WC were highly correlated to body fat at all ages (all r>0.8) but at 10 years WC was more strongly correlated than BAZ (r=0.94 WC vs r=0.88 BAZ, P<0.05); conversely, WHtR was significantly associated with body fat from 7 years (r=0.85) and 10 years (r=0.88). WHR was unrelated all over the period studied at all ages. Anthropometrical adiposity indicators became associated to cardiometabolic markers only from 7 years on with associations being slightly higher at 10 years, particularly for adiponectin and lipid markers. At all ages, BAZ, WC and WHtR performed similarly as cardiometabolic markers (P<0.05) while WHR was a slightly weaker marker. CONCLUSIONS: Relationship between anthropometrical indicators of adiposity and cardiometabolic markers becomes stronger from 7 years onwards; BAZ, WC and WHtR perform similarly as markers of cardiometabolic risk at least until 10 years of age.

Evaluation of simple body composition methods: assessment of validity in prepubertal Chilean children.

BACKGROUND/OBJECTIVE: The aim of this study was to assess the validity of body fatness estimations based on skinfolds and bioelectrical iImpedance analyses (BIA) measurements compared to a three-component model (3C model) in prepubertal Chilean children, considering potential differences by sex and nutritional status. SUBJECTS/METHODS: Four hundred and twenty four Chilean children (198 females and 226 males) were assessed for body composition. Body fat percentage (BF%) was evaluated by Skinfold equations (Slaughter, Ramirez and Huang) and Bioelectrical impedance (BIA: Tanita BC-418MA) using both the equipment and the Ramirez equation. Measurements based on a 3C model constructed from total body water estimates by isotope dilution and from body volume estimates by air displacement plethysmography were used as gold standard. RESULTS: Coefficient of determination (R2) values were higher in overweight and in the whole group of both gender. All slopes were differed significantly from 1, and most intercepts were significantly different from 0. Skinfold Equations: an underestimation of BF% was found for all equations, being higher with the Slaughter equation. BIA: Tanita underestimated BF% in all groups, whereas Ramirez equation shows an overestimation. CONCLUSIONS: Skinfolds and bio-impedance equations serve well to rank children according to their BF%. However, these methods are not accurate for describing body composition in prepubertal Chilean children.

Early adiposity rebound is associated with metabolic risk in 7-year-old children.

BACKGROUND: Early adiposity rebound (AR <5 years) has been consistently associated with increased obesity risk, but its relationship with metabolic markers is less clear; in addition, the biologic mechanisms involved in these associations have not been established. OBJECTIVE: The objective of this study was to assess the association between timing of AR and metabolic status at age 7 years, evaluating the potential role of adiposity, adipose functionality and skeletal maturation in this association. DESIGN: We estimated the age of AR from the body mass index (BMI) trajectories from 0 to 7 years in 910 children from the Growth and Obesity Chilean Cohort Study (GOCS). At 7 years, we measured waist circumference (WC) and blood glucose, insulin, triglycerides and high-density lipoprotein-cholesterol levels and constructed a metabolic risk score. We also measured percent fat mass (adiposity), plasma concentrations of leptin and adiponectin (adipose functionality) and bone age using wrist ultrasound (skeletal maturation). RESULTS: We found that 44% of the children had an AR <5 years. Earlier AR was associated with larger WC (ß: 5.10 (95% confidence interval (CI): 4.29-5.91)), higher glucose (ß: 1.02 (1.00-1.03)), insulin resistance (ß Homeostatic Model Assessment: 1.06 (1.03-1.09)), triglycerides (ß: 10.37 (4.01-6.73)) and adverse metabolic score (ß: 0.30 (0.02-0.37)). Associations decreased significantly if adiposity was added to the models (i.e. ß WC: 0.85 (0.33-1.38)) and, to a lesser extent, when adipokines (i.e. ß WC: 0.73 (0.14-1.32)) and skeletal maturation (i.e. ß WC: 0.65 (0.10-1.20)) were added. CONCLUSION: In GOCS children, AR at a younger age predicts higher metabolic risk at 7 years; these associations are mostly explained by increased adiposity, but adipose dysfunction and accelerated skeletal maturation also have a role.

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

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.

Nutrition transition in Latin America: the case of Chile.

The nutritional situation of Latin America is changing rapidly from one characterized by underweight and stunting to one where chronic diseases such as cancer, cardiovascular disease, and type 2 diabetes are increasingly prevalent. In Chile, under-nutrition has virtually disappeared, but rising obesity rates and risk factors for chronic diseases indicate the need to modify existing programs and emphasize prevention of diet-related chronic diseases.

Obesity trends in Latin America: transiting from under- to overweight.

Latin America is undergoing a rapid demographic and nutritional transition. A recent WHO/PAHO survey on obesity in the region revealed an increasing trend in obesity as countries emerge from poverty, especially in urban areas. In contrast, in middle income countries, obesity tends to decline as income increases; this is especially so in women. Dietary changes and increasing inactivity are considered the crucial contributory factors that explain this rise. The end result is a progressive rise in overweight and obesity, especially in low income groups who improve their income and buy high fat/high carbohydrate energy-dense foods. Intake of these foods increases to the detriment of grains, fruits and vegetables. Most aboriginal populations of the Americas have changed their diet and physical activity patterns to fit an industrialized country model. They now derive most of their diet from Western foods and live sedentary and physically inactive lives. Under these circumstances they develop high rates of obesity, insulin resistance and type 2 diabetes. Supplementary feeding programs are common in the region; the number of beneficiaries significantly exceeds the malnourished. Weight-for-age definition of undernutrition without assessment of length will overestimate the dimension of malnutrition and neglect the identification of stunted overweight children. Providing food to low income stunted populations may be beneficial for some, although it may be detrimental for others, inducing obesity especially in urban areas. Defining the right combination of foods/nutrients, education and lifestyle interventions that are required to optimize nutrition and health is a present imperative.

[Height increase among school children assisting to first grade during the last decade in Chile]. / Aumento en la estatura de escolares que ingresaron al primer año básico durante la última década.

BACKGROUND: In most developing countries, the prevalence of height deficit among schoolchildren correlates well with poverty. Therefore this indicator is frequently used to monitor the quality of life of a population. AIM: To assess the changes in height of children entering first grade during the last decade. MATERIAL AND METHODS: The records of the Chilean Board of School Assistance, that recollects anthropometric data on 80% of the national population of school age children, were used. For the purposes of this analysis, data from first graders in 1987, 1990, 1993 and 1996 were considered. The absolute variation of height, height for age Z scores were calculated. Children were grouped by sex and by age, using 7 years old as the cutoff value. RESULTS: During the last decade, height has increased significantly in men and women and in all ages. The increase has been greater in younger children. There is a higher proportion of males than women with height deficit. CONCLUSIONS: The increase in height can be attributed to the improvement in social, economic and biological conditions of our population as well as to the targeting strategies of existing food programs.

[Obesity, an unresolved challenge in Chile]. / Obesidad: un desafío pendiente en Chile.

Socioeconomic and demographic changes in Chile, have modified its epidemiological profile. At the present time, the most important public health problems are non communicable chronic diseases, specially cardiovascular ailments. The prevalence of cardiovascular risk factors has also increased and obesity stands out. This review analyzes the present situation of obesity and other cardiovascular risk factors of nutritional origin, in Chile, and proposes intervention alternatives. At the present time 7% preschool children, 12% of school children, 24% of pregnant women, 10% of male adults and 24% of female adults are obese. This higher prevalence is even more pronounced in women of low socioeconomic level. Risk factors associated to obesity are an inadequate diet, with a higher consumption of fats and refined foods, sedentariness and hyperlipidemia. Primary and secondary care strategies must be devised to face this growing problem.

[Obesity in Chilean preschool children: anthropometric evolution and socioeconomic determinants]. / Obesidad en el preescolar: evolución antropométrica y determinantes socioeconómicos.

BACKGROUND: The prevalence of obesity among low-income preschool children has increased in Chile. AIM: To compare the anthropometric evolution of obese and non obese children from birth and to determine the influence of maternal body composition and socioeconomic variables with childhood obesity. SUBJECTS AND METHODS: Using a case control design, 237 obese, 449 normal and 54 overweight 4 year old low income children, attending 8 public outpatient clinics in Santiago, were studied. Anthropometric data since birth to the moment of the study was gathered from the clinical charts at the clinics. RESULTS: Z scores for height/age and weight/height were significantly higher at all ages, excepting height/age in boys at the moment of birth. At the moment of the study, obese and overweight children were four and one cm taller than the normal weight controls. Maternal body mass index (odds ratio 3.07), being a first child, having a working mother, to have a telephone at home and birth weight were the variables significantly associated with obesity, according to an adjusted effects analysis. CONCLUSIONS: The strong association of maternal and offspring obesity implies that the prevention of childhood obesity must consider health actions directed towards mothers as well.

[Effect of a supplementary feeding program on height growth in children]. / Efecto de un programa de refuerzo alimentario sobre el crecimiento en talla de una población infantil.

The general objective of this study was to compare the variation exhibited in height/age by a group of low income children (when they were under 2 years) who had a mild deficit in this parameter and who received an important supplement, with another group with the same deficit who did not receive it. To achieve this objective we obtained a sample of children who were beneficiaries of Chile's National Complementary Feeding Program. The experimental group included children from the so called reinforced component of that program and the control group from the basic one. The results showed that after 12 months of observation, both groups gained in height, being those increments statistically significantly. Interestingly, the improvement was greater in the control group. The authors argue that with the nutritional situation that our country exhibits presently, that is, a very small percentage of low wt/age and around 18% to 24% of low income children with a mild deficit in height, a general improvement of the family's economic status probably produces a larger effect on this indicator than a high calorie/protein supplement.

[Evaluation of the Reinforced subprogram of the Chilean National supplemental Nutrition Program]. / Evaluación de la modalidad de Refuerzo del Programa Nacional de Alimentación Complementaria de Chile.

Chile's National Supplementary Feeding Program constitutes the main food intervention program of the country. Its annual budget amounts to US $ 65 million covering approximately 55% of the national population of children under 6 years of age. It includes two subprograms, the Basic one for normally growing children and the Reinforced one for undernourished children and those at risk of becoming undernourished. This last group amounted in 1990 to 17% of the total, receiving 50% of the food distributed. This study is the first evaluation carried out on the Reinforced subprogram, having as general objective to measure its efficiency in terms of the change in the nutritional status of the targeted children. Presently, children under two are targeted if a) are undernourished by wt/ht (< -1 S.D. NCHS) or b) have less weight increase than 75% of the Ministry of Health's norm (similar to NCHS) during two consecutive health controls. The only way these children are discharged is, if during three consecutive controls (monthly) they increase more than 75% of the same norm. The analysis involved nutritional evaluations at birth, when the children were targeted and when they were discharged, showing that the improvement of their nutritional status was very unsatisfactory.

[Evaluation of a teaching program of nutrition in agronomy]. / Validación de un programa de enzeñanza de nutrición en agronomia.

The purpose of this study was to evaluate a set of teaching materials on food, nutrition and agriculture, adapted at the Institute of Nutrition and Food Technology (INTA), University of Chile, within the scope of a project with AID and the School of Agronomy of the Chilean Catholic University (U. C.) aimed at incorporating the teaching of human nutrition into the curriculum of Latin American agronomists. A one semester course (54 hours) was given to 22 students of the 7th semester of Agronomy and two Ecuatorian agronomists (with AID scholarships). A set of knowledge evaluation instruments was applied at the beginning and at the end of the course. A total of 83.3% of the students passed the final examination (with more than 75% of correct answers). The difference between the initial and final performance was highly significant (p less than 0.001). According to the students' and teachers' opinions, the general textbook and the teachers book contributed effectively to meet the learning objectives whereas the students handbook needed some modifications. In conclusion, the program is an important contribution to the education of agronomists in a new conception of their role in regard to improvement of the nutritional status and quality of life of the rural population. With a few minor modifications, a final version to be used in the countries of the Region, shall soon become available.