Juliana Kain

Smart food policies for obesity prevention

Prevention of obesity requires policies that work. In this Series paper, we propose a new way to understand how food policies could be made to work more effectively for obesity prevention. Our approach draws on evidence from a range of disciplines (psychology, economics, and public health nutrition) to develop a theory of change to understand how food policies work. We focus on one of the key determinants of obesity: diet. The evidence we review suggests that the interaction between human food preferences and the environment in which those preferences are learned, expressed, and reassessed has a central role. We identify four mechanisms through which food policies can affect diet: providing an enabling environment for learning of healthy preferences, overcoming barriers to the expression of healthy preferences, encouraging people to reassess existing unhealthy preferences at the point-of-purchase, and stimulating a food-systems response. We explore how actions in three specific policy areas (school settings, economic instruments, and nutrition labelling) work through these mechanisms, and draw implications for more effective policy design. We find that effective food-policy actions are those that lead to positive changes to food, social, and information environments and the systems that underpin them. Effective food-policy actions are tailored to the preference, behavioural, socioeconomic, and demographic characteristics of the people they seek to support, are designed to work through the mechanisms through which they have greatest effect, and are implemented as part of a combination of mutually reinforcing actions. Moving forward, priorities should include comprehensive policy actions that create an enabling environment for infants and children to learn healthy food preferences and targeted actions that enable disadvantaged populations to overcome barriers to meeting healthy preferences. Policy assessments should be carefully designed on the basis of a theory of change, using indicators of progress along the various pathways towards the long-term goal of reducing obesity rates.

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.

The epidemiological transition: need to incorporate obesity prevention into nutrition programmes.

BACKGROUND Trends in the nutritional status for developing countries that are undergoing rapid economic growth indicate a decrease in protein-energy malnutrition (PEM) with an associated rise in obesity prevalence. OBJECTIVE This paper analyses how supplementary feeding programmes may contribute to rising obesity trends, what factors may explain this phenomenon, and potential strategies to avoid obesity in malnutrition prevention efforts. DESIGN AND SETTING This is a descriptive study of changes in nutritional status of infants and young children in Chile and the possible impact of supplementary feeding programmes on the rise in prevalence of obesity. We explored the changes in anthropometric indices before and after receiving food programme benefits and the use of targeting strategies as a way to combine the need to promote optimal growth while preventing obesity. RESULTS Evaluation of the change in nutritional status from participants in Chilean supplementary feeding programmes has shown that targeting strategies have been inadequate as children mainly modify their weight-for-age and weight-for-height, while their length-for-age remains practically unchanged. CONCLUSIONS Monitoring length-for-age as well as weight-for-length is necessary to permit the identification of stunted overweight and obese children, as they should not be given excess energy. Energy supplementation should be adjusted according to activity level, securing adequate micronutrient density. PEM prevention programmes need periodic evaluation, including targeting of beneficiaries, definition of real needs and possible effect on obesity.

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

Nutrition, child growth, and chronic disease prevention

Countries undergoing the nutrition transition are experiencing a progressive increase in obesity and nutrition‐related chronic diseases (NRCDs). In transitional countries, stunting (shortness for age) and micronutrient deficiencies (iron, vitamin A, and zinc) in children coexist with obesity and NRCDs originating the double burden of nutritional disease. The causal web for obesity and NRCDs is complex and multifaceted; changes in diet and physical activity of the population are likely the main concurrent determinant factors. However, recent evidence suggests that specific patterns of prenatal and postnatal growth are also potential contributors. Evidence indicates that intervention strategies to prevent malnutrition should emphasize improvements in linear growth in the first 2–3 years of life rather than aim at gaining weight. Avoiding excessive weight gain relative to height gain (BMI) is especially relevant after the first 2 years of life. Routine assessment of child growth based on the new World Health Organization (WHO) standard, defining energy needs based on the recent Food and Agricultural Organization (FAO)/WHO norms, and providing critical micronutrients to support lean mass growth are critical to prevent obesity and NRCDs starting early in the life course. These actions should contribute in the prevention and control of obesity in childhood and thus help prevent NRCDs in future generations of adults.

How can the Developmental Origins of Health and Disease (DOHaD) hypothesis contribute to improving health in developing countries

The relevance of nutrition during pregnancy and early infancy in defining short-term health and survival has been well established. However, the Developmental Origins of Health and Disease (DOHaD) paradigm provides a framework to assess the effect of early nutrition and growth on long-term health. This body of literature shows that early nutrition has significant consequences on later health and well-being. In this article, we briefly present the main consequences of malnutrition that affect human growth and development and consider how the DOHaD paradigm, with its evolutionary implications, might contribute to better addressing the challenge of improving nutrition. We examine how this paradigm is particularly appropriate in understanding the health and nutrition transition in countries that face the double burden of nutrition-related diseases (acute malnutrition coexisting with obesity and other chronic diseases). We focus on stunting (low height-for-age) to examine the short- as well as long-term consequences of early malnutrition with a life-course, transgenerational, and multidisciplinary perspective. We present current global and regional prevalence of stunting and discuss the need to reposition maternal and infant nutrition not only in health and nutrition intervention programs but also in consideration of the emerging research questions that should be resolved to better orient program and policy decisions.

Obesity indicators and cardiometabolic status in 4-y-old children

BACKGROUND In adults and adolescents, obesity is positively associated with cardiovascular disease risk factors; however, evidence in preschool children is scarce. OBJECTIVE The objective was to assess the relations between obesity indicators and cardiometabolic risk factors in 324 Chilean children 4 y of age. DESIGN We collected anthropometric measurements and calculated general indicators of obesity [weight, body mass index (BMI), sum of 4 skinfold thicknesses, percentage fat, and body fat index] and central obesity (waist circumference, waist-to-hip ratio, waist-to-height ratio, and truncal fatness based on skinfold thickness). We measured blood sample concentrations of C-reactive protein, interleukin-6, homeostasis model assessment of insulin resistance, triglycerides, and total, LDL, and HDL cholesterol. We used correlation and multiple linear regression analyses. RESULTS The prevalence of obesity (BMI-for-age z score >2, World Health Organization 2006), central obesity (> or = 90th percentile, third National Health and Nutrition Examination Survey), and lipid disorders was high (13%, 11%, and > or = 20%, respectively), and 70% of the children had at least one cardiometabolic risk factor. Most correlations between obesity and central obesity indicators were moderate to strong (0.40 < r < 0.96). Obesity was positively but weakly associated with C-reactive protein in both sexes and with homeostasis model assessment of insulin resistance only in girls (all r < 0.3, P < 0.05). Obesity indicators were unrelated to interleukin-6 and lipid concentrations (P > 0.05). Overall, obesity indicators explained, at most, 8% of the variability in cardiometabolic risk factors. CONCLUSIONS Obesity and central obesity were common, and most of the children had at least one cardiometabolic risk factor, particularly lipid disorders. Obesity and central obesity indicators were highly intercorrelated and, overall, were weakly related to cardiometabolic status. At this age, body mass index and waist circumference were poor predictors of cardiometabolic status.

Accelerated growth in early life and obesity in preschool Chilean children.

In Chile, childhood obesity rates are high. The purpose of this article is to compare BMI growth characteristics of normal (N), overweight (OW), and obese (OB) 5‐year olds from 0 to 5 years and explore the influence of some prenatal factors on these patterns of growth. The study was done on a retrospective cohort of 1,089 5‐year olds with birth weight >2,500 g. Weight and height were obtained from records at nine occasions (0–36 months); at 52 and 60 months, we measured them. At 60 months, children were classified as N, OW, and OB. At each age, BMI and z‐score of BMI (BMI Z) differences were compared among groups. The influence of birth weight, pre‐pregnancy BMI, and prenatal variables (weight gain, smoking, and presence of diabetes and preeclampsia) on BMI Z differences between N and OB was also explored. Adiposity rebound (AR) was not observed for the N, although for the OW, it occurred ∼52 months and for the OB at ∼24 months. BMI Z differences between N and OB were significant from birth, but were greatest between 6–12 and 36–52 months. Additional adjustment by birth weight, pre‐pregnancy BMI, and prenatal variables decreased the BMI Z differences for the first 24 months with virtually no effect after this age. Accelerated growth in OB children from post‐transition countries occurs immediately after birth, much earlier than the AR. The influence of prenatal factors on adiposity acquisition may extend at most until 2 years of life, although BMI gains thereafter are more related to postnatal variables.