Three Decades of New Zealand Adults Obesity Trends: An Estimation of Energy Imbalance Gaps Using System Dynamics Modeling

Understanding the obesity dynamics by socioeconomic status in Colombian and Mexican cities using a system dynamics model

Purpose

This paper aims to enrich understanding of the obesity transition among socioeconomic status (SES) strata by gender and age in cities of Colombia and Mexico. The study uses harmonized data from the Salud Urbana en América Latina (SALURBAL) study.

Methods

A population-level system dynamics model was developed using 2010 and 2015 data from Colombia and 2012 and 2016 data from Mexico (national health surveys). The model simulates the prevalence of different BMI categories (i.e., not overweight, overweight, obese) stratified by gender, age, and SES, in the SALURBAL cities (aggregated to the country level) of Colombia and Mexico from 2010 to 2050. Sample sizes for Colombia in 2010 and Mexico in 2012 were 7420 and 5785 children (<5 years), 21601 and 14413 children and adolescents (5-17 years), and 46597 and 20464 adults (18-64 years), respectively. Sample sizes for Colombia in 2015 and Mexico in 2016 were 4450 and 907 children, 12468 and 2350 children and adolescents, and 90430 and 3413 adults, respectively.

Results

For men in Colombia and Mexico, the burden of obesity is projected to increase among lower SES adults over time. Colombian women show similar patterns observed in men but the burden of obesity was already greater in the lower SES groups as early as 2012. In Mexican women, the burden of obesity in 2012 is higher in the lower SES population; however, the prevalence of obesity is projected to increase at a faster rate in the higher SES population. Patterns for children aged 0-14 years differed by gender and country.

Conclusions

The model suggests that the prevalence of obesity among SES strata by age and gender in SALURBAL cities of Colombia and Mexico are likely to change over time, and predicts their possible evolution through the different stages of the obesity transition.

Impacts of early psychological changes on correlates of weight-loss maintenance: Seeking increased precision for sustained behavioural obesity treatment effects

ISSUE ADDRESSED

Obesity is an increasing worldwide health issue. In affluent English-speaking countries, obesity ranges from ~28% (Australia) to ~42% (United States) of the adult population. Enabling weight loss beyond an initial 6 months is an unresolved challenge.

METHODS

Women with obesity participated in community-based obesity treatments incorporating either cognitive-behavioural methods emphasizing self-regulatory skills development (n = 106) or typical information/education processes (n = 47). Psychosocial, behavioural, and weight changes were measured.

RESULTS

Significant overall improvements in exercise-related self-regulation and self-efficacy, mood, physical activity/exercise (PA/exercise), diet, and weight were found from baseline-month 6 (weight-loss phase) and baseline-month 12, but not from months 6-12 (weight-loss maintenance phase). Significantly greater improvements were found in the cognitive-behavioural group. Within the weight-loss phase, changes in both PA/exercise and diet significantly contributed to the explained variance in weight loss, whereas within the weight-loss maintenance phase, only change in PA/exercise was a significant predictor. There was no significant relationship of weight loss across phases. Months 6-12 change in PA/exercise significantly mediated relationships of changes in self-regulation→weight, mood→weight, and self-efficacy→weight. Earlier scores and score changes in mood and self-efficacy significantly impacted the subsequent parallel relationships.

CONCLUSIONS

Cognitive-behavioural methods affect psychosocial changes leading to initial changes in diet, PA/exercise, and weight. Those changes then impact subsequent changes in PA/exercise-a primary malleable correlate of maintained weight loss. SO WHAT?: This research extended previous findings to better-inform behavioural obesity-treatment foci to address the pervasive public health problem of attaining and sustaining weight loss. Findings related to PA/exercise will help impact health-promotion outcomes.

Understanding the dynamics of the obesity transition associated with physical activity, sedentary lifestyle, and consumption of ultra-processed foods in Colombia

OBJECTIVE

We investigate the obesity transition at the country- and regional-levels, by age, gender, and socioeconomic status (SES) and its relationship to three health behavior attributes, including physical activity (PA), sedentary activities (ST), and consumption of ultra-processed foods (CUPF) within the urban population of Colombia, from 20,010 to 2050.

METHODS

The study is informed by cross-sectional data from ENSIN survey. We used these data to develop a system dynamics model that simulates the dynamics of obesity by body mass index (BMI) categories, gender, and SES. This model also uses a conservative co-flow structure for three health-related behaviors (PA, ST, and CUPF).

RESULTS

At the national level, our results indicate that the burden of obesity is shifting towards populations with lower SES as the gross domestic product (GDP) increases, particularly women aged 20-59 years with lower SES. Among this group of women, the highest burden of obesity is among those who do not meet the PA, ST and CUPF recommendations. At the regional level, our findings suggest that the regions are at different stages in the obesity transition.

CONCLUSIONS

The burden of obesity is shifting towards women with lower SES as GDP increases at the national level and across several regions. This obesity transition is paralleled by a high prevalence of women from low SES groups who do not meet the minimum recommendations for PA, CUPF, and ST. Our findings can be used by decision-makers to inform age- and SES- specific policies seeking to tackle the obesity.

Psychometric Testing: Self-Efficacy for Calorie Control and Exercise

Enhancing self-efficacy for calorie control and exercise is a crucial strategy for successful weight management. This study developed and psychometrically tested a 13-item quick checklist for assessing self-efficacy for calorie control and exercise (QCSE-CCE). A convenience sample of 425 adults between 18 and 69 years old completed the QCSE-CCE online. The principle axis factor analysis and a parallel analysis demonstrated a three-factor structure that accounts for 72.8% of the total variance. The confirmatory factor analysis indicated a good model fit (χ²/df = 2.168, GFI = .913, AGFI = .873, RMR = .049, RMSEA = .073, CFI = .959). The predictive validity was adequate (.38 < r < .39, p < .000), with Cronbach's alphas ranging from .87 to .91. The test-retest demonstrated good stability (r = .69; p < .001). The QCSE-CCE is a valid and reliable instrument for assessing self-efficacy for calorie control and exercise for weight management purposes.

Energy Imbalance Gap, Anthropometric Measures, Lifestyle, and Sociodemographic Correlates in Latin American Adults-Results from the ELANS Study

Overweight and obesity are often explained by an imbalance between energy intake and expenditure. This, in addition to metabolic effects, makes it difficult to assess the real state of individual energy balance. This study aims to analyze the energy gaps between intake and expenditure in the adult population of Latin America, as well as its relationships with sociodemographic variables and nutrition status, to draw an epidemiological perspective based on the trends observed. The energy imbalance gap was used to this end. The difference between energy intake and expenditure can be applied as a reference to explain whether weight equilibrium can prevent weight gain. Moreover, the energy imbalance gap allows for a better understanding of the design of public health policies. Using data from the Latin American Study of Nutrition and Health, the energy imbalance gap in adult population from eight Latin-American countries was assessed in 5994 subjects aged from 19-65. Usual dietary intake was measured using two non-consecutive 24 h dietary recalls. The sociodemographic questionnaire was supplemented by anthropometric measurements. Physical activity was measured through the long International Physical Activity Questionnaire. Energy expenditure was obtained using the basal metabolic rate. For the overall sample, the mean energy intake was 1939.1 kcal (95% CI: 1926.9; 1951.3), the mean of energy expenditure was 1915.7 kcal (95% CI: 1906.4; 1924.9), and the mean of energy imbalance gap was 23.4 kcal (95% CI: 11.9; 35.0). Results show that energy intake and expenditure were higher in men. Moreover, subjects aged 19-34, of high socioeconomic level, who completed high school, were mestizos and were of normal weight consumed the highest number of calories. Overall, a positive energy imbalance gap was observed. Overweight and obese from Argentina, Costa Rica, Ecuador, Peru, and Venezuela showed a significantly lower energy imbalance gap than underweight subjects. These findings confirm the high variability of energy imbalance gap and the accompanying correlates of energy intake and expenditure. Further research is needed to specifically address interventions in low and middle-income countries such as many in Latin America, to help reduce the prevalence of obesity and eradicate undernutrition.

Trends in Energy Imbalance Gap and Body Weight Status in the Japanese Adult Population: A System Dynamics Approach

Background

The double burden of malnutrition is a growing public health problem in Japan. We estimated the dynamics of the energy imbalance gap (EIG) (average daily difference between energy intake and expenditure) to explain trends in the prevalence of underweight, overweight, and obese Japanese adults.

Methods

We used individual-level data on body height and weight from the National Health and Nutrition Surveys from 1975 to 2015. We calibrated a validated system dynamics model to estimate the EIG for Japanese adults aged 20 to 74 years by survey year, sex, and weight status classified by the body mass index (BMI).

Results

The overall EIG for men increased from 2.3 kcal/day in 1975 to 4.7 kcal/day in 1987 and then decreased to 2.3 kcal/day in 2015. The overall EIG for women consistently decreased from 4.3 kcal/day in 1975 to −0.5 kcal/day in 2015. By BMI class, the EIG for men with a BMI of <30 kg/m² began to decrease around 1990, indicating a deceleration in the prevalence of overweight and obese men. The EIG consistently decreased for women with a BMI of <25 kg/m² and reached negative values from the late 2000s to early 2010s, indicating a gradual decrease in the prevalence of overweight and obese women.

Conclusions

The dynamics of the EIG were different across sex and weight groups. Public health interventions should target a further decrease in the EIG for normal-weight, overweight, and obese men and a stop in the decreasing trends of the EIG in underweight and normal-weight women.

An Experimental Comparison of the Impact of 'Warning' and 'Health Star Rating' FoP Labels on Adolescents' Choice of Breakfast Cereals in New Zealand

This research investigated the performance of the red, octagonal Vienna Convention traffic ‘STOP’ sign as a front of pack (FoP) warning nutritional label. While the Vienna Convention traffic light system is an established FoP label, the potential of the ‘STOP’ sign in the role has not been investigated. The performance of the ‘STOP’ label was compared with that of a single star (low nutritional value) Australasian Health Star Rating (HSR) label using a fractionally replicated Latin square design. The labels were presented on choice diads of cold breakfast cereal packets. The sample of 240 adolescents aged 16–18 was drawn from a secondary school in the South Island of New Zealand. A large and significant main effect was observed at the p < 0.01 level for the difference between the ’STOP’ sign and the control condition (no nutritional FoP label), and at p < 0.05 for the difference between the HSR and the ‘STOP’ label. There was no significant difference between the HSR FoP and the control condition. A significant non-additivity (interaction) (p < 0.01) was also observed via the fractional replication. The results indicate that the Vienna Convention ‘STOP’ sign is worthy of further research with regard to its potential as an FoP nutritional label.

Healthy and Climate-Friendly Eating Patterns in the New Zealand Context

BACKGROUND

The global food system is driving both the climate crisis and the growing burden of noncommunicable disease. International research has highlighted the climate and health co-benefit opportunity inherent in widespread uptake of plant-based diets. Nevertheless, uncertainty remains as to what constitutes healthy and climate-friendly eating patterns in specific world regions.

OBJECTIVES

Using New Zealand as a case study, this research investigates the extent to which potential contextual differences may affect the local applicability of international trends. It further examines the potential for demand-end avenues to support a transition toward a healthier, more climate-friendly food system in New Zealand.

METHODS

A New Zealand-specific life-cycle assessment (LCA) database was developed by modifying cradle to point-of-sale reference emissions estimates according to the New Zealand context. This food emissions database, together with a New Zealand-specific multistate life-table model, was then used to estimate climate, health, and health system cost impacts associated with shifting current consumption to align with dietary scenarios that conform to the New Zealand dietary guidelines (NZDGs).

RESULTS

Whole plant foods, including vegetables, fruits, legumes, and whole grains were substantially less climate-polluting (1.2-1.8 kgCO2e/kg) than animal-based foods, particularly red and processed meats (12-21 kgCO2e/kg). Shifting population-level consumption to align with the NZDGs would confer diet-related emissions savings of 4-42%, depending on the degree of dietary change and food waste minimization pursued. NZDG-abiding dietary scenarios, when modeled out over the lifetime of the current New Zealand population, would also confer large health gains (1.0-1.5 million quality-adjusted life-years) and health care system cost savings (NZ$14-20 billion).

DISCUSSION

Guideline-abiding dietary scenarios, particularly those that prioritize plant-based foods, have the potential to confer substantial climate and health gains. This research shows that major contextual differences specific to New Zealand's food system do not appear to cause notable deviation from global trends, reinforcing recent international research. https://doi.org/10.1289/EHP5996.