Maartje Poelman

Small, medium, large or supersize? The development and evaluation of interventions targeted at portion size

In the past decades, portion sizes of high-caloric foods and drinks have increased and can be considered an important environmental obesogenic factor. This paper describes a research project in which the feasibility and effectiveness of environmental interventions targeted at portion size was evaluated. The studies that we conducted revealed that portion size labeling, offering a larger variety of portion sizes, and proportional pricing (that is, a comparable price per unit regardless of the size) were considered feasible to implement according to both consumers and point-of-purchase representatives. Studies into the effectiveness of these interventions demonstrated that the impact of portion size labeling on the (intended) consumption of soft drinks was, at most, modest. Furthermore, the introduction of smaller portion sizes of hot meals in worksite cafeterias in addition to the existing size stimulated a moderate number of consumers to replace their large meals by a small meal. Elaborating on these findings, we advocate further research into communication and marketing strategies related to portion size interventions; the development of environmental portion size interventions as well as educational interventions that improve people’s ability to deal with a ‘super-sized’ environment; the implementation of regulation with respect to portion size labeling, and the use of nudges to stimulate consumers to select healthier portion sizes.

Behavioural strategies to control the amount of food selected and consumed

Several factors within the food environment may stimulate overconsumption. The present study aimed to (1) identify behavioural strategies to cope with this environment to control the amount of food consumed, (2) examine the feasibility and usefulness of the strategies, and (3) evaluate the association between the strategies and body mass index (BMI). After the literature was screened for evidence of factors that contribute to the consumption of large amounts of food, 32 behavioural strategies were identified to overcome these influences (study 1). Subjectively reported feasibility and usefulness of the 32 behavioural strategies in weight management were explored using a pretest post-test study (study 2: n = 52). Additionally, two cross-sectional questionnaire studies (study 3a: n = 120 and study 3b: n = 278) were conducted to evaluate the association between the 32 behavioural strategies and BMI. The strategies were subjectively reported as feasible and useful in weight management. Frequent use of strategies discriminated non-overweight from overweight individuals, but did not discriminate overweight from obese individuals. In conclusion, the findings provided preliminary evidence for the acceptability and validity of the strategies. The effectiveness of the strategies for controlling the amount consumed should be further investigated, especially in overweight and obese participants.

Portion Size: Latest Developments and Interventions

Purpose of ReviewThe aim of this review is to provide an overview of (1) underlying mechanisms of the effect of portion size on energy intake, (2) external factors explaining the portion size effect and (3) interventions and measurements aimed at food portion size.Recent FindingsPrevious studies have shown that portion sizes have increased in recent decades. Many experimental studies have been conducted to unravel the mechanisms underlying the portion-size effect on food intake (e.g. the appropriateness mechanism, the ‘unit bias’ mechanism, the ‘previous experience/expectation’ mechanism, the ‘visual cue’ mechanism and the ‘bite size’ mechanism). In addition, external factors have been found to drive food portion selection and consumption (e.g. value for money, mindless eating, levels of awareness, estimation bias. Research on several interventions (ranging from ‘providing information’ to ‘eliminating choice’) have been conducted, but remain scarce, especially intervention studies in which portion size is a key focus in weight loss. Moreover, only three new instruments with respect to portion control behavior have been developed.SummaryThere is considerable evidence for the portion-size effect on energy intake. However, the work on interventions targeting portion size and measurements for portion control behavior are limited. Moreover, from the literature it is not yet clear what type of interventions work best, for whom and in what context.

The Development and Evaluation of an Internet-Based Intervention to Increase Awareness About Food Portion Sizes: A Randomized, Controlled Trial

OBJECTIVE To develop a Web-based tool (PortionSize@warenessTool) and to evaluate its effectiveness in increasing awareness of reference serving sizes and factors that may contribute to overeating in response to large portion sizes. METHODS A randomized, controlled trial (intervention, n = 167; control, n = 143) was conducted. The authors measured awareness of reference serving size and overeating triggers from larger portions by an online questionnaire, assessed at baseline and 1 week later. Exposure dose reflected online activity (eg, number of Web pages viewed). Process evaluation data were collected within the intervention group. RESULTS The intervention group demonstrated significantly higher awareness of reference serving sizes (η(2) = .062; P < .001) and overeating triggers from larger portions (η(2) = .061; P < .001) at posttest. Also, the authors observed a dose-dependent effect that led to improved awareness. CONCLUSIONS AND IMPLICATIONS The PortionSize@warenessTool constitutes a promising tool to improve portion size awareness.

Package size and manufacturer-recommended serving size of sweet beverages: a cross-sectional study across four high-income countries.

OBJECTIVE To assess the mean package size and manufacturer-recommended serving size of sweet beverages available in four high-income countries: Australia, Canada, the Netherlands and New Zealand. DESIGN Cross-sectional surveys. SETTING The two largest supermarket chains of each country in 2012/2013. SUBJECTS Individual pack size (IPS) drinks (n 891) and bulk pack size (BPS) drinks (n 1904). RESULTS For all IPS drinks, the mean package size was larger than the mean serving size (mean (sd)=412 (157) ml and 359 (159) ml, respectively). The mean (sd) package size of IPS drinks was significantly different for all countries (range: Australia=370 (149) ml to New Zealand=484 (191) ml; P<0·01). The mean (sd) package size of Dutch BPS drinks (1313 (323) ml) was significantly smaller compared with the other countries (New Zealand=1481 (595) ml, Australia=1542 (595) ml, Canada=1550 (434) ml; P<0·01). The mean (sd) serving size of BPS drinks was significantly different across all countries (range: Netherlands=216 (30) ml to Canada=248 (31) ml; P<0·00). New Zealand had the largest package and serving sizes of the countries assessed. In all countries, a large number of different serving sizes were used to provide information on the amount appropriate to consume in one sitting. CONCLUSIONS At this point there is substantial inconsistency in package sizes and manufacturer-recommended serving sizes of sweet beverages within and between four high-income countries, especially for IPS drinks. As consumers do factor serving size into their judgements of healthiness of a product, serving size regulations, preferably set by governments and global health organisations, would provide consistency and assist individuals in making healthier food choices.

‘Obesogenic’ School Food Environments? An Urban Case Study in The Netherlands

(1) Background: This study aimed to explore and define socio-economic (SES) differences in urban school food environments in The Netherlands. (2) Methods: Retail food outlets, ready-to-eat products, in-store food promotions and food advertisements in public space were determined within 400 m walking distance of all secondary schools in the 4th largest city of The Netherlands. Fisher’s exact tests were conducted. (3) Results: In total, 115 retail outlets sold ready-to-eat food and drink products during school hours. Fast food outlets were more often in the vicinity of schools in lower SES (28.6%) than in higher SES areas (11.5%). In general, unhealthy options (e.g., fried snacks, sugar-sweetened beverages (SSB)) were more often for sale, in-store promoted or advertised in comparison with healthy options (e.g., fruit, vegetables, bottled water). Sport/energy drinks were more often for sale, and fried snacks/fries, hamburgers/kebab and SSB were more often promoted or advertised in lower SES areas than in higher SES-areas. (4) Conclusion: In general, unhealthy food options were more often presented than the healthy options, but only a few SES differences were observed. The results, however, imply that efforts in all school areas are needed to make the healthy option the default option during school time.

Relations between the residential fast-food environment and the individual risk of cardiovascular diseases in The Netherlands: A nationwide follow-up study:

Background The food environment has been hypothesized to influence cardiovascular diseases such as hypertension and coronary heart disease. This study determines the relation between fast-food outlet density (FFD) and the individual risk for cardiovascular disease, among a nationwide Dutch sample. Methods After linkage of three national registers, a cohort of 2,472,004 adults (≥35 years), free from cardiovascular disease at January 1st 2009 and living at the same address for ≥15 years was constructed. Participants were followed for one year to determine incidence of cardiovascular disease, including coronary heart disease, stroke and heart failure. Street network-based buffers of 500 m, 1000 m and 3000 m around residential addresses were calculated, while FFD was determined using a retail outlet database. Logistic regression analyses were conducted. Models were stratified by degree of urbanization and adjusted for age, sex, ethnicity, marital status, comorbidity, neighbourhood-level income and population density. Results In urban areas, fully adjusted models indicated that the incidence of cardiovascular disease and coronary heart disease was significantly higher within 500 m buffers with one or more fast-food outlets as compared with areas with no fast-food outlets. An elevated FFD within 1000 m was associated with an significantly increased incidence of cardiovascular disease and coronary heart disease. Evidence was less pronounced for 3000 m buffers, or for stroke and heart-failure incidence. Conclusions Elevated FFD in the urban residential environment (≤1000 m) was related to an increased incidence of cardiovascular heart disease and coronary heart disease. To better understand how FFD is associated with cardiovascular disease, future studies should account for a wider range of lifestyle and environmental confounders than was achieved in this study.

Food taxes and calories purchased in the virtual supermarket: a preliminary study

Purpose The purpose of this paper is to examine the effectiveness of three food taxation schemes on energy (kcal), saturated fat (gram) and sugar (gram) purchased in the virtual supermarket. Design/methodology/approach Based on the literature, three food taxation schemes were developed (sugar tax, saturated fat tax and a nutrient profiling tax) and implemented in the three-dimensional virtual supermarket. A randomized control trial was conducted to determine the differences in the amount of energy (kcal), saturated fat (gram) and sugar (gram) purchased for a one-week food basket. Findings In total, 191 Dutch adults were randomly assigned to a sugar-tax condition (n=48), a saturated fat-tax condition (n=37), a nutrient profiling-tax condition (n=62) and a control (no-tax) condition (n=44). Fully adjusted models indicated that compared to the no-tax condition, no significant effects of a sugar-tax condition (B: −2,041 kcal (95% CI −5,350 to 1,914)), saturated fat-tax condition (B: −2,717 kcal (95% CI −6,596 to 1,163)) or nutrient profiling-tax condition (B: −1,124 kcal (95% CI −4,538 to 2,292)) were found on the amount of energy purchased. Also, none of the taxation schemes showed significant effects on saturated fat or sugar purchased. Originality/value This is one of the first randomized controlled trials testing the effectiveness of a variety of food taxes in the virtual supermarket. This preliminary study provides important directions for future research (the design, results, as well as the lessons learned with respect to recruitment, incentives and technology).