The portion size effect on food intake. An anchoring and adjustment process?

Is Opioid Consumption Impacted by Study Participation? Maintenance of Fewer Opioid Refills With Reduced Prescription Quantity After Posterior Spinal Fusion in Adolescents With Idiopathic Scoliosis

BACKGROUND

Opioid overprescribing can lead to nonmedical opioid use. In a previous prospective study (STUDY), we showed that a standardized protocol involving preoperative education and reduced opioid prescription quantity decreased opioid use in idiopathic scoliosis patients following posterior spinal fusion (PSF). A potential limitation was the Hawthorne effect, where participant behavior changes due to observation. At STUDY conclusion, we continued the reduced opioid prescriptions but discontinued the formal preoperative education. This retrospective study (post-STUDY) assessed if opioid refill requests increased outside of a study setting.

METHODS

Post-STUDY included patients aged 10 to 17 years who underwent PSF for idiopathic scoliosis between January 2022 and December 2023 and were discharged with a prescription of ≤30 oxycodone doses. Patients were excluded if they had previous spine surgery or were discharged with an opioid other than oxycodone. Demographics, perioperative variables, and opioid refill requests were compared with the data from STUDY, in which patients were aware their opioid use would be tracked. Patient-reported outcomes were collected via Scoliosis Research Society-22r (SRS-22r) surveys.

RESULTS

The post-STUDY cohort included 67 patients (69% female). The average age at the time of PSF was 13.9 years (range, 11 to 17 y). The mean number of levels fused was slightly higher (10.9 vs. 10.0, P=0.04), and intraoperative estimated blood loss was lower (211 vs. 303 mL, P<0.01) compared with the STUDY cohort. Demographics, preoperative major curve magnitude, surgery duration, and length of hospital stay were similar. The percentage of patients who requested and received opioid refills between the post-STUDY and STUDY cohorts was also similar [6/67 (9%) vs. 3/49 (6%), P=0.30]. SRS-22r showed improvements in self-image, satisfaction, and mean total score from preoperative to postoperative.

CONCLUSIONS

Reduced opioid prescriptions did not result in increased opioid refill requests in adolescents undergoing PSF for idiopathic scoliosis outside of a study setting. While formal preoperative discussions about postoperative pain control are important, other factors likely influence opioid use. Further research should explore characteristics that predispose patients to require higher amounts of postoperative opioids.

LEVEL OF EVIDENCE

Level III-therapeutic.

Does 'portion size' matter? Brain responses to food and non-food cues presented in varying amounts

Larger portions of food elicit greater intake than smaller portions of food, particularly when foods are high in energy density (kcal/g; ED). The neural mechanisms underlying this effect remain unclear. The present study used fMRI to assess brain activation to food (higher-ED, lower-ED) and non-food (office supplies) images presented in larger and smaller (i.e., age-appropriate) amounts in 61, 7-8-year-olds (29 male, 32 female) without obesity. Larger amounts of food increased activation in bilateral visual and right parahippocampal areas compared to smaller amounts; greater activation to food amount (larger > smaller) in this cluster was associated with smaller increases in food intake as portions increased. Activation to amount (larger > smaller) was stronger for food than office supplies in primary and secondary visual areas, but, for office supplies only, extended into bilateral parahippocampus, inferior parietal cortex, and additional visual areas (e.g., V7). Activation was greater for higher-vs. lower-ED food images in ventromedial prefrontal cortex for both larger and smaller amounts of food; however, this activation extended into left lateral orbital frontal cortex for smaller amounts only. Activation to food cues did not differ by familial risk for obesity. These results highlight potentially distinct neural pathways for encoding food energy content and quantity.

Food portion sizes: trends and drivers in an obesogenic environment

The prevalence of overweight and obesity in children and adults has increased worldwide. A strong environmental factor contributing to the obesity epidemic is food portion size (PS). This review evaluates the current evidence linking food PS to obesity, examines the effects of PS on energy intake (EI), and discusses the drivers of food PS selection. The leading causes of the rise in PS include globalisation, intensive farming methods, the impact of World War II, due to shortage of staple foods, and the notion of 'waste not, want not'. Large PS of energy-dense foods may stimulate overconsumption, leading to high EI levels. However, the studies have not shown a cause-and-effect relationship, due to confounding factors. Important mechanisms explaining the attractiveness of larger PS leading to higher EI levels are value for money, portion distortion, labels on food packaging, and tableware. Consumers depend on external rather than internal PS cues to guide consumption, irrespective of satiety levels. Further research is recommended on food consumption patterns to inform policymakers and provide information and insights about changes in diet.

Do Pictograms on Medication Packages Cause People to Consult Package Inserts Less Often? If so, With What Consequences?

Overall, pharmaceutical pictograms seem to improve medication adherence. However, little is known about how warning pictograms (e.g., "do not drive after taking") on medication packages influence patients' information-seeking strategies such as consulting the package insert (PI) to determine other features such as the correct dosage. In this online study, participants (358 students) were presented with three fictitious scenarios (e.g., headache after alcohol consumption; factor scenario) in which medication use would be contraindicated. Each scenario was accompanied by a visual presentation of a medication package that could contain three possible pictogram selections or arrangements (factor warning); some arrangements contained pictograms relevant to the situation represented by the scenario, while others did not. Participants had to decide which dosage of the represented medication they were allowed to take in the given scenario. In making this decision, they could consult the PI or not. Overall, in two out of the three scenarios (driving and pregnancy), medication packages with relevant pictograms resulted in fewer PI consultations but led to more correct dosage decisions ("no pill") than packages with irrelevant pictograms. Pictograms generally played no role in either the review of the PI consultation or dosage decisions in the alcohol scenario. Providing warning-relevant pictograms on medication packages can help people know when they should not take medication even without reading the PI.

Development and validation of a new methodological platform to measure behavioral, cognitive, and physiological responses to food interventions in real time

To fully understand the causes and mechanisms involved in overeating and obesity, measures of both cognitive and physiological determinants of eating behavior need to be integrated. Effectively synchronizing behavioral measures such as meal micro-structure (e.g., eating speed), cognitive processing of sensory stimuli, and metabolic parameters, can be complex. However, this step is central to understanding the impact of food interventions on body weight. In this paper, we provide an overview of the existing gaps in eating behavior research and describe the development and validation of a new methodological platform to address some of these issues. As part of a controlled trial, 76 men and women self-served and consumed food from a buffet, using a portion-control plate with visual stimuli for appropriate amounts of main food groups, or a conventional plate, on two different days, in a random order. In both sessions participants completed behavioral and cognitive tests using a novel methodological platform that measured gaze movement (as a proxy for visual attention), eating rate and bite size, memory for portion sizes, subjective appetite and portion-size perceptions. In a sub-sample of women, hormonal secretion in response to the meal was also measured. The novel platform showed a significant improvement in meal micro-structure measures from published data (13 vs. 33% failure rate) and high comparability between an automated gaze mapping protocol vs. manual coding for eye-tracking studies involving an eating test (ICC between methods 0.85; 90% CI 0.74, 0.92). This trial was registered at Clinical Trials.gov with Identifier NCT03610776.

Preoperative Patient Education and Smaller Prescription Quantity Reduce Opioid Use After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis: Results of a Prospective Study

BACKGROUND

Most opioids prescribed postoperatively are unused. Leftover opioids are a major source of nonmedical opioid use among adolescents. Postoperative opioid use has also been associated with prescription quantity. Our purpose was to evaluate the effect of preoperative patient education and implementation of evidence-based prescribing guidelines on opioid use and pain level after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS).

METHODS

AIS patients aged 10 to 17 years undergoing PSF were prospectively enrolled [postintervention cohort (POST-INT)]. Previous data on 77 patients showed median consumption of 29 doses of oxycodone after PSF [preintervention cohort (PRE-INT)]. All eligible patients during the study period were discharged with 30 doses of oxycodone and standard nonopioid analgesics. Only study participants received education on postoperative pain control. Demographics, radiographic/surgical data, pain level, and patient-reported outcomes were collected. Requests for opioid refills were documented.

RESULTS

Forty-nine patients were enrolled. POST-INT was divided into low (L, ≤8 doses), average (AVE, 9-25), and high (H, >25) opioid use groups. Demographics, radiographic/surgical data, pain level, and patient-reported outcomes were similar between the groups. However, there was a difference in days of oxycodone use, doses consumed in the first week, and leftover doses ( P <0.001). Comparison to the PRE-INT L (≤16 doses), AVE (17 to 42), and high (H, >42) use groups showed that POST-INT L and AVE consumed less oxycodone (L: P =0.002; AVE: P <0.001). Also, the overall POST-INT cohort had fewer mean days of oxycodone use (5.6 vs. 8.9, P <0.001) and doses used in the first week (14 vs. 23, P <0.001) compared with the PRE-INT cohort. Subanalysis showed fewer study participants requested and received an opioid refill [3/49 patients (6%)] compared with eligible patients who declined to participate, withdrew, or missed enrollment [8/35 patients (23%)] ( P =0.045).

CONCLUSIONS

Preoperative patient education and smaller prescription quantity successfully reduced opioid use while maintaining excellent pain control after PSF for AIS. Setting expectations regarding postoperative pain management is critical, as nonstudy participants were significantly more likely to request an opioid refill.

LEVEL OF EVIDENCE

Level II-therapeutic.

Changes in Package Sizes of Savoury Snacks through Exploration of Euromonitor and Industry Perspectives

Portion sizes of many energy-dense and nutrient-poor foods and drinks have increased in the past decade, whereas our understanding of the pattern of changes in package sizes remains limited. This study aimed to determine changing trends in sales and package sizes of savoury snacks in Australia, the USA, Japan and Hong Kong, and to investigate industry perspectives for these changes. Sales data (units per capita) between 2006−2020 on savoury snacks were extracted from the Euromonitor International database. Industry perspectives on package size changes were extracted systematically from selected databases, company reports and related websites following the PRISMA-ScR guidelines. The findings showed that sales per capita of savoury snacks of all package sizes increased across all four countries/regions between 2006−2020. Although changes in the proportion of smaller (<100 g) versus larger (>100 g) package size sales in each country/region over time were modest, Japan and Hong Kong exhibited a consistently higher proportion of smaller package sales compared with Australia and the USA (83.3%, 64.4%, 44.3%, 20.2%, respectively). Industry perspectives showed that increasing consumer health consciousness, demands for convenience and portion control were the main contributors to decreasing package sizes of savoury snacks. Industry reports from 2020 showed an increase in larger package size sales due to consumer purchasing behaviour amidst the COVID-19 pandemic.

Effect of acute dietary- versus combined dietary and exercise-induced energy deficits on subsequent energy intake, appetite and food reward in adolescents with obesity

BACKGROUND

Acute dietary-induced energy deficits have been shown to favor compensatory appetitive responses. The aim of this study was to compare energy intake (EI), appetite sensations and the hedonic responses to equivalent energy deficits induced by dietary restriction alone and combined with exercise in adolescents with obesity.

METHODS

In a within-subjects design, seventeen adolescents with obesity (12-16 years, Tanner stage 3-5, 6 males) randomly completed three 14 h conditions: (i) control (CON); (ii) deficit induced by diet only (Def-EI) and; (iii) deficit induced by combined diet and physical exercise (Def-mixed). Breakfast and lunch were calibrated to generate a 500 kcal deficit in Def-EI and 250 kcal deficit in Def-mixed. A 250 kcal deficit was created through a cycling exercise set at 65% VO_2peak in Def-mixed. Ad libitum EI, macronutrients and relative EI (REI) were assessed at dinner, subjective appetite sensations taken at regular intervals, and food reward measured before dinner.

RESULTS

EI at dinner was significantly lower in Def-EI compared to CON (p = 0.014; Effect size (ES): -0.59 [-1.07; -0.12]), with no difference between Def-mixed and both CON and Def-EI. Total REI was lower in both deficit conditions compared with CON (Def-mixed: p < 0.001; ES: -3.80 [-4.27; -3.32], Def-EI: p < 0.001; ES: -4.90 [-5.37; -4.42] respectively), indicating incomplete compensation for the energy deficits. Absolute protein ingestion at dinner was lower in Def-EI than Def-mixed (p = 0.037; ES: -0.50 [-0.98; -0.03]) and absolute lipid ingestion was lower in Def-EI than in CON (p = 0.033; ES: -0.51 [-0.99; -0.04]). A higher proportion of protein and a lower proportion of carbohydrates was observed in Def-mixed than in Def-EI (p = 0.078; ES: -0.42 [-0.90; 0.04] and p = 0.067; ES: 0.44 [-0.03; 0.92] respectively). Total area under the curve for appetite sensations were similar between conditions. Explicit liking for sweet relative to savoury food was lower in Def-mixed compared to CON (p = 0.027; ES: -0.53 [-1.01; -0.06]) with no difference in food reward between Def-EI and CON.

CONCLUSION

Neither of the two acute isoenergetic deficits led to subsequent appetitive compensation, with the dietary deficit even inducing a lower ad libitum EI at the subsequent dinner. Further studies are needed to better understand the appetitive response to dietary and exercise energy balance manipulations in this population.

"This snack is too small - I'll take a different one": Quantifying 'norm' and 'choice' boundaries to inform effective portion-reduction strategies

Previous research suggests that portion sizes can be categorised as 'normal' or 'abnormal' and that reduced portions which are still categorised as normal do not promote compensatory responses in intake. However, a critical question remains - will consumers choose a reduced portion product from among standard portion competitors? For the first time, we explore the effects of portion reduction on food choice. Participants (N = 45) categorised 20 different portions (range 40-420 kcal) of five snacks as normal or abnormal (to quantify individual 'norm boundaries' for each food) and rated their desire to eat each snack. Using a 2-alternative forced choice hypothetical task, we then calculated a 'choice boundary' by offering smaller portions of their most-desired snack (range 40-240 kcal) alongside standardised portions (240 kcal) of the less-desired foods. Boundaries were derived using probit analysis (choice boundary mean = 185.8 kcal, SD = 54, norm boundary mean = 127.3 kcal, SD = 49.5) and these deviated significantly (p < .01, d = 0.98, mean difference = 58.0 kcal, SD = 59.1). Critically, this shows that only a small reduction - where the product is still considered normal - can nudge a consumer to select an alternative. Choice boundaries were also affected by differences in desire to eat; when two foods were desired to a similar degree, only minor reductions in the size of the favourite food elicited a switch in choice. Together, these findings indicate that portion reduction can also influence food choice, highlighting the importance of measuring choice boundaries before reformulating commercial products.

Can Visual Cues to Portion Size Reduce the Number of Portions of Consumed? Two Randomized Controlled Trials

Background

Since 1950, the portion size of many snack foods has more than doubled and obesity rates have tripled. Portion size determines energy intake, often unwittingly.

Purpose

This paper tests whether salient visual cues to portion size on the packaging of high fat, sugar, or salty (HFSS) snacks can reduce consumption.

Methods

Two preregistered randomized controlled trials (N = 253 and N = 674) measured consumption in a lab and the home environment. Cues were salient, labeled stripes that demarcated single portions. Participants were randomized to cue condition or control. Consumption was measured without awareness.

Results

The main preregistered effect of the visual cue was not statistically significant. There was some variation by subgroup. In Study 1, men were more likely to eat the whole can of potato chips than women but significantly reduced consumption when visual cues were on the pack. The effect size was large: the number of men eating more than the recommended portion fell by 33%. Study 2 monitored household consumption of chocolate biscuits (cookies) sent to family homes in gift packs. Again, the main effect was nonsignificant but there was significant subgroup variation. When the person receiving the biscuits was female, households were more likely to eat more than the recommended portion per person per day, but less likely when the visual cues were displayed. The gender of the eaters was not known. The effect size was again large: the number of households eating more than the recommended portion fell by 26%. Households with children were also less likely to open packs with visual cues compared to control packs. Both studies recorded significant increases in the likelihood of observing serving size information, together with confusion about what it means.

Conclusions

The studies offer some evidence that salient visual cues could play a role in tackling the high consumption of unhealthy snacks, but the effects are confined to specific subgroups and warrant further investigation.

That's My Cue to Eat: A Systematic Review of the Persuasiveness of Front-of-Pack Cues on Food Packages for Children vs. Adults

Packaging is increasingly recognized as an essential component of any marketing strategy. Visual and informational front-of-pack cues constitute salient elements of the environment that may influence what and how much someone eats. Considering their overwhelming presence on packaging of non-core foods, front-of-pack cues may contribute to the growing rates of overweight and obesity in children and adults. We conducted a systematic review to summarize the evidence concerning the impact of front-of-pack cues on choices and eating behaviors. Four electronic databases were searched for experimental studies (2009-present). This resulted in the inclusion of 57 studies (in 43 articles). We identified studies on children (3-12 years) and adults (≥ 18 years), but no studies on adolescents (12-18 years). The results suggest that children and adults are susceptible to packaging cues, with most evidence supporting the impact of visual cues. More specifically, children more often choose products with a licensed endorser and eat more from packages portraying the product with an exaggerated portion size. Adults' eating behaviors are influenced by a range of other visual cues, mainly, package size and shape, and less so by informational cues such as labels.

Reductions to main meal portion sizes reduce daily energy intake regardless of perceived normality of portion size: a 5 day cross-over laboratory experiment

BACKGROUND

Smaller portions may help to reduce energy intake. However, there may be a limit to the magnitude of the portion size reduction that can be made before consumers respond by increasing intake of other food immediately or at later meals. We tested the theoretical prediction that reductions to portion size would result in a significant reduction to daily energy intake when the resulting portion was visually perceived as 'normal' in size, but that a reduction resulting in a 'smaller than normal' portion size would cause immediate or later additional eating.

METHODS

Over three 5-day periods, daily energy intake was measured in a controlled laboratory study using a randomized crossover design (N = 30). The served portion size of the main meal component of lunch and dinner was manipulated in three conditions: 'large-normal' (747 kcal), 'small-normal' (543 kcal), and 'smaller than normal' (339 kcal). Perceived 'normality' of portion sizes was determined by two pilot studies. Ad libitum daily energy intake from all meals and snacks was measured.

RESULTS

Daily energy intake in the 'large-normal' condition was 2543 kcals. Daily energy intake was significantly lower in the 'small-normal' portion size condition (mean difference - 95 kcal/d, 95% CI [- 184, - 6], p = .04); and was also significantly lower in the 'smaller than normal' than the 'small-normal' condition (mean difference - 210 kcal/d, 95% CI [- 309, - 111], p < .001). Contrary to predictions, there was no evidence that the degree of additional food consumption observed was greater when portions were reduced past the point of appearing normal in size.

CONCLUSIONS

Reductions to the portion size of main-meal foods resulted in significant decreases in daily energy intake. Additional food consumption did not offset this effect, even when portions were reduced to the point that they were no longer perceived as being normal in size.

TRIAL REGISTRATION

Prospectively registered protocol and analysis plan: https://osf.io/natws/; retrospectively registered: https://clinicaltrials.gov/ct2/show/NCT03811210.

Are Big Five Traits and Facets Associated With Anchoring Susceptibility?

Anchoring, the assimilation of judgments to previously considered values, is one of the most robust findings in psychology, and researchers have been increasingly interested in finding individual difference moderators of anchoring effects. Several investigations have examined the relation between Big Five traits and anchoring susceptibility, but previous studies have produced a confusing and contradictory pattern of results. We identify limitations of previous work and report a large preregistered study ( N = 945) to test whether Big Five traits and facets relate to anchoring. We find no significant relations between any traits or facets and anchoring susceptibility. We discuss the implications of our results and future directions for research on individual differences in anchoring susceptibility.

A review of evidence supporting current strategies, challenges, and opportunities to reduce portion sizes

Although there is considerable evidence for the portion-size effect and its potential impact on health, much of this has not been successfully applied to help consumers reduce portion sizes. The objective of this review is to provide an update on the strength of evidence supporting strategies with potential to reduce portion sizes across individuals and eating contexts. Three levels of action are considered: food-level strategies (targeting commercial snack and meal portion sizes, packaging, food labels, tableware, and food sensory properties), individual-level strategies (targeting eating rate and bite size, portion norms, plate-cleaning tendencies, and cognitive processes), and population approaches (targeting the physical, social, and economic environment and health policy). Food- and individual-level strategies are associated with small to moderate effects; however, in isolation, none seem to have sufficient impact on food intake to reverse the portion-size effect and its consequences. Wider changes to the portion-size environment will be necessary to support individual- and food-level strategies leading to portion control.

Tasting with your eyes: Sensory description substitutes for portion size

A field study conducted in a diner explored whether a sensory rich description of an indulgent dessert prompts consumers to be willing to pay just as much for a small serving as for a large serving. Diner customers (N = 809) who ordered an entrée received a free piece of chocolate cake if they filled out a questionnaire indicating the amount of cake they ate, their willingness to pay (WTP) for the cake, their fullness after eating, and other measures. A between-subjects 2 × 3 design varied the serving size of the cake (6 oz. vs. 12 oz.) and the description of the cake (no description control, nutrition description, or sensory description). Self-reported amount eaten showed a smaller portion size effect in the nutrition description condition than in the other two conditions. Of primary interest, relative to the other conditions, the sensory description caused customers to be willing to pay as much for the small piece as for the large piece and to feel almost as full after eating from the small piece as from the large piece. These results indicate that a sensory rich description makes customers' evaluations of an indulgent dessert less sensitive to serving size. As a result, sensory descriptions can be used to make customers just as content with a small dessert as they would be with a large dessert.

The effects of salience of the sound of food on consumption

In order to promote their products, food marketers use labels (e.g., crunchy) to make salient the sound created by the food when it is eaten. Will merely making the sound of the food salient (without changing its actual sound) affect consumption? The extant literature is silent on this question. Addressing this gap, we propose that the mere salience of the food's sound can impact consumption. In three studies, we find that the salience of the food's sound increases consumption because it enhances consumers' auditory experience of the sound of food and increases taste evaluations. However, the salience of the food's sound decreases consumption when experience of the food's sound is impaired or when consumption monitoring is high. The paper's findings advance research on auditory perceptions of food, food labeling, and food consumption, and offer guidance on how to enhance enjoyment and prevent overeating of sound-salient food.

Lower socioeconomic status is associated with higher intended consumption from oversized portions of unhealthy food

Socioeconomic status is one of the strongest predictors of obesity, and of living in deprived neighbourhoods with unhealthy food environments. Little is known, however, about the psychological processes that translate features of such environments into socioeconomic differences in eating behaviour. One important feature of unhealthy food environments is the prevalence of oversized portions of unhealthy food. The present study tested whether individuals with lower socioeconomic status intend to consume more from large portions than those with higher socioeconomic status, and examined the psychological processes underlying this effect. A large-scale online experiment was conducted in which participants (N = 511) indicated how much they would eat from small and large portions of healthy and unhealthy snacks. The mediating effects of trait impulsivity and perceptions of how much was considered appropriate to eat were also assessed. Participants with lower socioeconomic status intended to eat more from the large portions than from the small portions of the unhealthy snacks, which would equate to a potential 15-22% increase in energy intake. These effects were partially mediated by trait impulsivity and perceptions of how much is appropriate to eat. These findings point to a significant health burden of low socioeconomic status: when exposed to unhealthy food environments, specific psychological processes might increase the amount of unhealthy food those with lower socioeconomic intend to consume. This study critically informs the emerging understanding of the psychology of socioeconomic status and eating behaviour.

Comparison between serving sizes of cakes and muffins sold in Australian supermarkets and coffee shop chains

AIM

Cakes and muffins are commonly consumed discretionary foods that have increased significantly in portion size over the past decades. The present study aimed to (i) investigate serving sizes and energy per serving of cakes and muffins sold in supermarkets and coffee chains, (ii) compare to standard discretionary serves and (iii) propose feasible and appropriate serving size recommendations.

METHODS

Serving sizes and energy content of cakes and muffins were collected from four major Australian supermarkets (n = 219) and eight coffee chains (n = 248) between March and April 2017 and classified into eight categories and compared using Mann-Whitney tests. Median energy per serving of cakes and muffins from supermarkets and coffee chains were compared to the Australian Dietary Guidelines standard serve of 600 kJ for discretionary food.

RESULTS

The median serving size of cakes and muffins from supermarkets, 58 g (interquartile range, IQR: 47-83) and their energy content, 915 kJ (IQR: 745-1243) were significantly smaller compared with coffee chain equivalents, 148 g (IQR: 115-171, P < 0.001) and 1805 kJ (IQR: 1436-2004, P < 0.001), respectively. The majority of cakes and muffins exceeded the Australian Dietary Guidelines standard serve (78% from supermarkets and 99% from coffee chains).

CONCLUSIONS

The larger servings of cakes and muffins sold in coffee chains contain nearly double the energy content of smaller servings sold in supermarkets. We recommend reference serving sizes for industry and food retail are set for this category, in combination with consumer education to guide consumers to select appropriate portion sizes.

Shared Concerns and Opportunity for Joint Action in Creating a Food Environment That Supports Health

The food industry is a for-profit industry with high relevance to universal eating disorders prevention. To date, policy which targets the food industry and food environment has been underutilized in efforts to decrease the incidence of eating disorders and associated risk factors. In contrast, food policy has been extensively leveraged with the aim of reducing the incidence of obesity. While philosophical misalignments with these later efforts may have constituted an obstacle to identifying the food environment as a key target for eating disorders prevention, food policy is an area where shared interests can be found. Specifically, a shared goal of obesity and eating disorders prevention efforts is creating a food environment that supports health, while minimizing the influence of the food industry that profits from the sale of highly palatable, processed foods and “diet” foods and from increasing portions of foods served and eaten.

Plate-clearing tendencies and portion size are independently associated with main meal food intake in women: A laboratory study

BACKGROUND

Larger portion sizes of food promote increased food intake, although the mechanisms explaining the portion size effect are unclear. In the present study we examined whether the tendency to clear one's plate when eating is associated with greater food intake in response to larger portion size.

METHOD

We recruited female participants who were either self-reported habitual plate clearers (N = 48) or non-plate clearers (N = 41) into a laboratory study. In a between-subjects design, participants were served either a 'normal' (500 g) or 'large' (1000 g) portion of pasta for lunch and ate as much as they desired.

RESULTS

There was no significant interaction found between portion size and plate-clearing tendencies; portion size had a similar sized effect on food intake in both plate clearers and non-plate clearers. A significant main effect of portion size was found, whereby participants consumed significantly more when served the large versus the normal portion (100.55 g difference, p < .001, η_p²  = 0.16). There was also a significant main effect of plate clearing; participants with a tendency to clear their plate when eating consumed significantly more than non-plate clearers (68.21 g difference, p = .006, η_p²  = 0.08).

CONCLUSIONS

The tendency to clear one's plate when eating was associated with increased food intake during a lunchtime meal. Increasing the portion size of the lunchtime meal increased food intake, although the tendency for a larger portion size to increase food intake was observed irrespective of participant plate-clearing tendencies.

Research into food portion size: methodological aspects and applications

Portion sizes for certain foods have been increasing dramatically in recent years alongside obesity rates, concurring with the phenomenon of the portion size effect (more is consumed when more is offered). Portion size may be defined based on different purposes such as for dietary assessment, or therapeutic advice or food labelling, resulting in a variety of measurement methods and specifications. This situation has resulted in disagreements on establishing portion size recommendations by manufacturers, food distributors, restaurants, health professionals and policy makers, contributing to confusion amongst consumers on the amounts of food to be consumed, and potentially increasing the likelihood of overeating and other obesity-related behaviours. Such variability is also reflected in the research field making comparison across studies on portion size difficult. The aim of this review is to provide an overview of definitions and methods used in research to evaluate portion-size related outcomes, including methods to estimate amounts consumed by individuals as part of dietary assessment; methods to analyse cognitive mechanisms related to portion size behaviour; and methods to evaluate the impact of portion size manipulations as well as individual plus environmental factors on portion size behaviour. Special attention has been paid to behavioural studies exploring portion size cognitive processes given the lack of previous methodological reviews in this area. This information may help researchers, clinicians and other stakeholders to establish clearer definitions of portion size in their respective areas of work and to standardise methods to analyse portion size effects.

Impact of various factors on stock-induced food waste in Indian weddings

Purpose

Weddings in India have become more extravagant in recent years. The ostentation goes well with the food also. Hundreds of varieties and great stock of food served making it a wasteful affair which would lead to the unsustainable demand for the natural resources. The purpose of this paper is to link the stock-induced consumption phenomenon with food waste generation in Indian weddings.

Design/methodology/approach

This study begins with the identification of the factors which would be responsible to make the food consumption stock-induced. A system dynamics (SD) model is developed using SD software STELLA (version 10.0) to assess the amount of stock-induced food waste. The impact of the factors on this waste is analyzed and estimation is made about the financial implications of this waste. Different scenarios have been analyzed to arrive at a most desirable scenario in the Indian context. Finally, the paper provides the recommendations for managerial implications to prevent the potential disastrous consequences of this waste.

Findings

A rigorous simulation analysis was conducted for different food-serving scenarios. The outcome of SD analysis shows that an enormous amount of food is wasted in the form of stock-induced consumption and dustbin waste. Impact analysis of factors on waste generation reveals that food wastage in marriages is entirely a behavioral phenomenon and can be controlled by exercising self and enforced behavioral control measures. Waste cost estimation gives an insight about the severity of the topic for policy making.

Social implications

The study has a very high social relevance and facilitates decision makers to take required actions to mitigate the stock-induced food waste in marriages. The study conducted will encourage the researchers to use SD in analyzing complex systems for quantitative estimations.

Originality/value

To the best of the authors’ knowledge, this is the first study that analyzes the food waste in Indian weddings in relation with the huge stock served using SD. The study provides valuable insights in the direction to make the country food secure.

On Moderator Detection in Anchoring Research: Implications of Ignoring Estimate Direction

Anchoring, whereby judgments assimilate to previously considered standards, is one of the most reliable effects in psychology. In the last decade, researchers have become increasingly interested in identifying moderators of anchoring effects. We argue that a drawback of traditional moderator analyses in the standard anchoring paradigm is that they ignore estimate direction—whether participants’ estimates are higher or lower than the anchor value. We suggest that failing to consider estimate direction can sometimes obscure moderation in anchoring tasks, and discuss three potential analytic solutions that take estimate direction into account. Understanding moderators of anchoring effects is essential for a basic understanding of anchoring and for applied research on reducing the influence of anchoring in real-world judgments. Considering estimate direction reduces the risk of failing to detect moderation.

Big hearts, small hands: a focus group study exploring parental food portion behaviours

BACKGROUND

The development of healthy food portion sizes among families is deemed critical to childhood weight management; yet little is known about the interacting factors influencing parents' portion control behaviours. This study aimed to use two synergistic theoretical models of behaviour: the COM-B model (Capability, Opportunity, Motivation - Behaviour) and Theoretical Domains Framework (TDF) to identify a broad spectrum of theoretically derived influences on parents' portion control behaviours including examination of affective and habitual influences often excluded from prevailing theories of behaviour change.

METHODS

Six focus groups exploring family weight management comprised of one with caseworkers (n = 4), four with parents of overweight children (n = 14) and one with parents of healthy weight children (n = 8). A thematic analysis was performed across the dataset where the TDF/COM-B were used as coding frameworks.

RESULTS

To achieve the target behaviour, the behavioural analysis revealed the need for eliciting change in all three COM-B domains and nine associated TDF domains. Findings suggest parents' internal processes such as their emotional responses, habits and beliefs, along with social influences from partners and grandparents, and environmental influences relating to items such as household objects, interact to influence portion size behaviours within the home environment.

CONCLUSION

This is the first study underpinned by COM-B/TDF frameworks applied to childhood weight management and provides new targets for intervention development and the opportunity for future research to explore the mediating and moderating effects of these variables on one another.

Debiasing Health-Related Judgments and Decision Making: A Systematic Review

BACKGROUND

Being confronted with uncertainty in the context of health-related judgments and decision making can give rise to the occurrence of systematic biases. These biases may detrimentally affect lay persons and health experts alike. Debiasing aims at mitigating these negative effects by eliminating or reducing the biases. However, little is known about its effectiveness. This study seeks to systematically review the research on health-related debiasing to identify new opportunities and challenges for successful debiasing strategies.

METHODS

A systematic search resulted in 2748 abstracts eligible for screening. Sixty-eight articles reporting 87 relevant studies met the predefined inclusion criteria and were categorized and analyzed with regard to content and quality. All steps were undertaken independently by 2 reviewers, and inconsistencies were resolved through discussion.

RESULTS

The majority of debiasing interventions ( n = 60) was at least partially successful. Optimistic biases ( n = 25), framing effects ( n = 14), and base rate neglects ( n = 10) were the main targets of debiasing efforts. Cognitive strategies ( n = 36) such as "consider-the-opposite" and technological interventions ( n = 33) such as visual aids were mainly tested. Thirteen studies aimed at debiasing health care professionals' judgments, while 74 interventions addressed the general population. Studies' methodological quality ranged from 26.2% to 92.9%, with an average rating of 68.7%.

DISCUSSION

In the past, the usefulness of debiasing was often debated. Yet most of the interventions reviewed here are found to be effective, pointing to the utility of debiasing in the health context. In particular, technological strategies offer a novel opportunity to pursue large-scale debiasing outside the laboratory. The need to strengthen the transfer of debiasing interventions to real-life settings and a lack of conceptual rigor are identified as the main challenges requiring further research.

Changes in Typical Portion Sizes of Commonly Consumed Discretionary Foods among Australian Adults from 1995 to 2011-2012

This study aimed to examine the changes in typical portion sizes of commonly consumed discretionary foods among Australian adults from 1995 to 2011–2012. Data of adults (age ≥19 years) from the 1995 Australian National Nutrition Survey and 2011–2012 National Nutrition and Physical Activity Survey were used. Typical portion sizes (median portion) of fourteen discretionary foods that contributed the most to energy intake were determined. Ten out of fourteen food categories demonstrated a significant change in kJ per typical portion from 1995 to 2011–2012 (p ≤ 0.001). kJ per typical portion increased for pizza, cake, sausage, cereal bar, processed meat, ice cream and wine, with pizza and cake demonstrating the largest increases (+570 kJ and +950 kJ in 2011–2012, respectively; both +66% above 1995). In contrast, kJ per typical portion of pastry, snack food and potato fries decreased by 10–40% over time, and did not change for biscuit, chocolate, sugar-sweetened beverage and beer. Similar changes were observed for grams per typical portion consumed. Temporal trends in typical portion sizes were similar according to age group, gender and socioeconomic status. The findings suggest that population-wide strategies that enable consumers to choose smaller portions of discretionary foods are needed to reduce the excess consumption of these products.

Portion Size: Latest Developments and Interventions

PURPOSE OF REVIEW

The 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 FINDINGS

Previous 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. There 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.

Food portion size and energy density evoke different patterns of brain activation in children

BACKGROUND

Large portions of food promote intake, but the mechanisms that drive this effect are unclear. Previous neuroimaging studies have identified the brain-reward and decision-making systems that are involved in the response to the energy density (ED) (kilocalories per gram) of foods, but few studies have examined the brain response to the food portion size (PS).

OBJECTIVE

We used functional MRI (fMRI) to determine the brain response to food images that differed in PSs (large and small) and ED (high and low).

DESIGN

Block-design fMRI was used to assess the blood oxygen level-dependent (BOLD) response to images in 36 children (7-10 y old; girls: 50%), which was tested after a 2-h fast. Pre-fMRI fullness and liking were rated on visual analog scales. A whole-brain cluster-corrected analysis was used to compare BOLD activation for main effects of the PS, ED, and their interaction. Secondary analyses were used to associate BOLD contrast values with appetitive traits and laboratory intake from meals for which the portions of all foods were increased.

RESULTS

Compared with small-PS cues, large-PS cues were associated with decreased activation in the inferior frontal gyrus (P < 0.01). Compared with low-ED cues, high-ED cues were associated with increased activation in multiple regions (e.g., in the caudate, cingulate, and precentral gyrus) and decreased activation in the insula and superior temporal gyrus (P < 0.01 for all). A PS × ED interaction was shown in the superior temporal gyrus (P < 0.01). BOLD contrast values for high-ED cues compared with low-ED cues in the insula, declive, and precentral gyrus were negatively related to appetitive traits (P < 0.05). There were no associations between the brain response to the PS and either appetitive traits or intake.

CONCLUSIONS

Cues regarding food PS may be processed in the lateral prefrontal cortex, which is a region that is implicated in cognitive control, whereas ED activates multiple areas involved in sensory and reward processing. Possible implications include the development of interventions that target decision-making and reward systems differently to moderate overeating.

What does it mean to eat an appropriate amount of food?

Norms of appropriateness have been used to account for the influence of a variety of external eating cues (e.g., social factors, portion size) on people's food intake. What is less clear is what, exactly, "appropriate" means. This study explored participants' conceptions of appropriate food intake. Two separate samples were included in this study: 121 university students (73% women) and 107 community members (100% women). Participants were asked to rate the extent to which several statements reflected the concept of "appropriate food intake" or "normal food intake" (1=Does not capture the definition at all; 7=Captures the definition perfectly). These statements included items referring to external eating cues (e.g., "Eating as much as other people", "Eating the entire portion of what you are served") and items referring to internal eating cues (e.g., "Eating an amount that will make you feel satisfied") or nutritional needs (e.g., "Eating a healthy amount"). Repeated measures ANOVAs indicated that participants consistently defined appropriate/normal intake in terms of internal eating cues and nutritional needs. In contrast, despite evidence indicating that perceptions of how much is an appropriate amount to eat are affected by external eating cues, external eating cues were ignored in participants' definition of appropriate/normal intake. The disconnect between how people define appropriate intake (i.e., in terms of internal cues) and what research shows affects norms of appropriateness (i.e., external cues) may reflect people's general unwillingness to acknowledge the influence of external eating cues on their food intake.

The Role of Social Norms in the Portion Size Effect: Reducing Normative Relevance Reduces the Effect of Portion Size on Consumption Decisions

People typically eat more from large portions of food than from small portions. An explanation that has often been given for this so-called portion size effect is that the portion size acts as a social norm and as such communicates how much is appropriate to eat. In this paper, we tested this explanation by examining whether manipulating the relevance of the portion size as a social norm changes the portion size effect, as assessed by prospective consumption decisions. We conducted one pilot experiment and one full experiment in which participants respectively indicated how much they would eat or serve themselves from a given amount of different foods. In the pilot (N = 63), we manipulated normative relevance by allegedly basing the portion size on the behavior of either students of the own university (in-group) or of another university (out-group). In the main experiment (N = 321), we told participants that either a minority or majority of people similar to them approved of the portion size. Results show that in both experiments, participants expected to serve themselves and to eat more from larger than from smaller portions. As expected, however, the portion size effect was less pronounced when the reference portions were allegedly based on the behavior of an out-group (pilot) or approved only by a minority (main experiment). These findings suggest that the portion size indeed provides normative information, because participants were less influenced by it if it communicated the behaviors or values of a less relevant social group. In addition, in the main experiment, the relation between portion size and the expected amount served was partially mediated by the amount that was considered appropriate, suggesting that concerns about eating an appropriate amount indeed play a role in the portion size effect. However, since the portion size effect was weakened but not eliminated by the normative relevance manipulations and since mediation was only partial, other mechanisms may also play a role.

Frosting on the cake: pictures on food packaging bias serving size

Objective

Food packaging often pictures supplementary extras, such as toppings or frosting, that are not listed on the nutritional labelling. The present study aimed to assess if these extras might exaggerate how many calories† are pictured and if they lead consumers to overserve.

Design

Four studies were conducted in the context of fifty-one different cake mixes. For these cake mixes, Study 1 compared the calories stated on the nutrition label with the calories of the cake (and frosting) pictured on the box. In Studies 2, 3 and 4, undergraduates (Studies 2 and 3) or food-service professionals (Study 4) were given one of these typical cake mix boxes, with some being told that cake frosting was not included on the nutritional labelling whereas others were provided with no additional information. They were then asked to indicate what they believed to be a reasonable serving size of cake.

Settings

Laboratory setting.

Subjects

Undergraduate students and food-service professionals.

Results

Study 1 showed that the average calories of cake and frosting pictured on the package of fifty-one different cake mixes exceed the calories on the nutritional label by 134 %. Studies 2 and 3 showed that informing consumers that the nutritional information does not include frosting reduces how much people serve. Study 4 showed that even food-service professionals overserve if not told that frosting is not included on the nutritional labelling.

Conclusions

To be less misleading, packaging should either not depict extras in its pictures or it should more boldly and clearly state that extras are not included in calorie counts.

Increasing the size of portion options affects intake but not portion selection at a meal

In an environment with large portion sizes, allowing consumers more control over their portion selection could moderate the effects on energy intake. We tested whether having subjects choose a portion from several options influenced the amount selected or consumed when all portion sizes were systematically increased. In a crossover design, 24 women and 26 men ate lunch in the lab once a week for 3 weeks. At each meal, subjects chose a portion of macaroni and cheese from a set of 3 portion options and consumed it ad libitum. Across 3 conditions, portion sizes in the set were increased; the order of the conditions was counterbalanced across subjects. For women the portion sets by weight (g) were 300/375/450, 375/450/525, and 450/525/600; for men the portions were 33% larger. The results showed that increasing the size of available portions did not significantly affect the relative size selected; across all portion sets, subjects chose the smallest available portion at 59% of meals, the medium at 27%, and the largest at 15%. The size of portions offered did, however, influence meal intake (P < 0.0001). Mean intake (±SEM) was 16% greater when the largest set was offered (661 ± 34 kcal) than when the medium and smallest sets were offered (both 568 ± 18 kcal). These results suggest that portions are selected in relation to the other available options, and confirm the robust effect of portion size on intake. Although presenting a choice of portions can allow selection of smaller amounts, the sizes offered are a critical determinant of energy intake. Thus, the availability of choices could help to moderate intake if the portions offered are within an appropriate range for energy needs.