Exploring consumer beliefs about novel fortified foods: A focus group study with UK-based older and younger adult consumers

Consuming 'nutritionally-enhanced' food products (including those that are fortified or enriched to deliver nutritional and functional properties) may help to improve overall diet quality and combat risks associated with malnutrition. However, fortification can negatively impact consumer acceptance, particularly where expected sensory properties of 'delivery' foods are affected by target ingredients. Here, we explored factors influencing consumer acceptability for six novel food products that had been fortified, including both savoury and sweet meal components (e.g., high protein dumplings, probiotic yoghurt drink). In person focus groups (25 consumers aged between 22 and 76 years old) were conducted with two stages; firstly, participants completed a blind taste test of products without awareness of fortification. Secondly, participants discussed products with awareness of additional ingredients and food properties. Reflexive thematic analysis showed that liking of sensory properties differed between foods, but informing participants about the fortification of products highlighted potential trade-offs between taste, health, price, and familiarity. Though taste and texture were generally prioritised by participants, positive perceptions of health benefits increased consumer willingness to buy, whilst both cost and uncertainty about product use were potential barriers. Trust of information was a key concern for labelling and product claims. These results highlight product features that may be optimised to support the success of fortified foods. Greater transparency when building product brands and improving consumer knowledge of fortification may also be important for longer-term consumer acceptance.

Associations between dietary variety, portion size and body weight: prospective evidence from UK Biobank participants

'Dietary variety' has been identified as a factor associated with food intake. Whilst this relationship may have longer-term benefits for body weight management when eating low-energy, nutrient-dense foods, it may increase the risk of overconsumption (and body adiposity) when foods are high energy density. This study sought to further explore pathways underpinning the relationship between dietary variety and body weight, by considering energy density as a moderating factor and portion size as a mediating factor in this relationship. Using prospective data from the UK Biobank, dietary variety scores (DVS), cumulative portion size and energy density were derived from 24-h dietary recall questionnaires at baseline and follow-up. BMI, whole-body fat percentage and fat-free mass were included as outcomes. Contrary to predictions, linear multiple regression models found some evidence of a negative, direct association between DVS and body weight outcomes at baseline (b = -0·13). Though dietary variety was significantly associated with larger portions across time points (b = 41·86-82·64), a moderated mediation effect was not supported at baseline or follow-up (Index ≤ 0·035). Taken together, these findings provide population-level evidence to support a positive association between variety and food intake, which in turn has potential implications for body weight management, both in terms of moderating food intake and benefitting diet quality.

Multi-component food-items and eating behaviour: What do we know and what do we need to know?

Multi-component food-items are single food products that comprise more than one food class, brought together usually via some form of processing. Importantly, individual components of the food-item remain discernible and sensorially distinguishable from each other (e.g., chocolate chip cookies or 'choc ice'). Despite a sizable research literature on the formulation of such products, there lacks a concomitant research literature on the effect(s) of multi-component food-items (compared to single component food-items) on eating behaviour. Considerable previous research has investigated the effect of multiple separate food items on food intake, portion size selection and palatability. However, studies rarely use test foods that capture the physical or chemical interactions between components that are characteristic of multi-component foods. Nevertheless, previous research and relevant theory allow us to generate hypotheses about how multi-component foods may affect eating behaviour; consideration of food variety and perceived sensory complexity suggest that consumption of multi-component foods are likely to increase perceived palatability of such foods, self-selected portion size and food intake. Moreover, many (but not all) multi-component foods would be considered ultra-processed, which is a driver of food intake in and of itself. One possibility is that food components brought together as part of a multi-component food-item interact to strongly drive eating behaviour. To explore this idea, researchers will need to work across disciplines to address various practical and methodological barriers including the technical preparation of test foods.

Testing an online measure of portion size selection: a pilot study concerned with the measurement of ideal portion size

BACKGROUND

Portion size is known to be a key driver of food intake. As consumed portions are often pre-planned, 'ideal portion size'-an individual's preferred meal size selected prior to eating-has been identified as a strong predictor of actual consumption. However, assessments of ideal portion size have predominantly relied on laboratory-based computer tasks, limiting use online. Therefore, this cross-sectional study sought to pilot test the validity of a web-based tool to measure ideal portion size.

METHODS

In an online study (N = 48), participants responded to images of a range of foods. Each food was photographed in a series of different portions and loaded into an 'image carousel' that would allow participants to change the size of the displayed portion by moving a slider left-to-right. Using this image carousel, participants selected their ideal portion size. They also completed measures of expected satiety and expected satiation and self-reported their age and body mass index (BMI). A non-parametric correlation matrix was used to explore associations between ideal portion size and identified predictors of food intake.

RESULTS

Supporting convergent validity of this measure, ideal portion size was significantly correlated with expected satiety (rs = .480) and expected satiation (rs = -.310) after controlling for effects of baseline hunger and fullness, consistent with past research. Similarly, supporting divergent validity of this measure, ideal portion size was not significantly correlated with age (rs = -.032) or BMI (rs = -.111,).

CONCLUSIONS

Pilot results support the validity of this web-based portion size selection tool used to measure ideal portion size, though further research is needed to validate use with comparisons to actual food intake.

Effect of food variety on intake of a meal: a systematic review and meta-analysis

BACKGROUND

Many studies have shown that food variety-the presence of multiple foods and/or sensory characteristics within and across meals-increases intake. However, studies report mixed findings, and effect size remains unclear.

OBJECTIVES

A systematic review and meta-analysis were conducted to 1) synthesize data across experimental studies that examined effects of variety on total meal intake, relative to a control condition with comparatively less variety; 2) quantify support for this effect; and 3) assist in the identification of important moderating factors (registration: CRD42019153585).

METHODS

In November 2019, we searched the following databases for relevant experimental studies, published in English from 1980, with human participants: PubMed, Cochrane Library, Web of Science, ClinicalTrials.gov, PsycINFO, and OpenGrey. This search was updated in September 2020. Means, standard deviations, and sample sizes were extracted from included articles, and Hedges' g was used to calculate effect sizes. Risk of bias was assessed using the Cochrane Collaboration's tool.

RESULTS

Of 7259 references identified in an initial search, 34 articles consisting of 37 studies contained sufficient information for review, and data from 30 studies (39 comparisons) were included in the meta-analysis. Results from a random-effects model showed a significant small to medium effect of variety on intake (in weight and energy), with greater variety being associated with increased consumption (Hedges' g = 0.405; 95% CI: 0.259, 0.552). However, heterogeneity was considerable across studies (I2 = 84%), and this was unexplained by subgroup analyses based on form of variety, test foods, sensory characteristics, age, sex, and body weight.

CONCLUSIONS

Our findings support the conclusion that variety is a robust driver of food intake. However, risk of bias was high across studies, and this review highlights methodologic limitations of studies. It is recommended that further attention is given to the development of preregistered, well-powered randomized controlled studies in eating behavior research.

Consumer perception of food variety in the UK: an exploratory mixed-methods analysis

BACKGROUND

'Food variety' is a key term that is frequently used in dietary guidelines around the world. Consuming a variety of foods - be it within a meal, across meals, or as part of the whole diet - is one factor that has been shown to increase food intake. However, little is known about consumer understanding of variety, and this may be a potential barrier to the success of dietary guidelines in today's 'obesogenic' environment. This research sought to explore 1) consumer recognition of different forms of variety, and 2) consumer definitions of variety.

METHODS

In an online study (N = 240), participants were asked to discuss a range of photographs depicting different forms of variety, and to directly define the term 'food variety'. They were unaware of the research aim.

RESULTS

Using a mixed methods approach, directed content analysis of these data showed that individuals referenced multiple forms of variety in the presence of food photographs. However, when asked to define variety, participants tended to only discuss variety in the context of the whole diet.

CONCLUSIONS

These findings emphasise a need to educate consumers about variety to encourage adherence to dietary guidelines and help consumers better manage their own food intake.

Construal beliefs moderate the usability and effectiveness of a novel healthy eating mobile app

Reduced self-control is a strong predictor of overeating and obesity. Priming a high construal level mind-set has been shown to enhance self-control and reduce snack consumption in the lab but the long-term and real-world effects are not known. The use of digital technology is an efficient way to deliver priming cues in real-world settings. Many mobile apps claim to support healthy eating but few are grounded in psychological theories of self-control. The aim of this study was to test the feasibility and effectiveness of a novel, construal-theory-based mobile app to promote self-control and healthy eating. In an exploratory analysis, the moderating influence of user characteristics was also examined. Using an iterative process involving users at every stage of the process, a prototype mobile app was developed. The final version included a high construal, self-control priming task, sent personalised reminder cues before each eating occasion, provided a just-in time 'crave-buster' for unanticipated eating opportunities and an optional food log. In a longitudinal trial the app was used over an eight-week period (N=71; 51 females; M (SD) Age = 33.34 (11.68) years; M (SD) BMI = 26.22 (4.94)) with pre-post measures of weight, percent body fat and dietary intake. The app received high usability ratings on the System Usability Scale (M=76.55; SD=11.35), however food intake, per cent body fat and weight pre- and post- app use showed no significant change (p>.05). Exploratory analyses showed that baseline construal belief moderated the extent to which engagement with the app predicted dietary changes (p<.05). These findings indicate that this novel app was user-friendly and effective but that this was dependent on the user's characteristics. Future development in this area should consider tailoring apps to the specific characteristics of the user for improved support and effectiveness.