Food-variety-focused labelling does not increase ideal portion size, expected fullness or snack intake

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.

Development of a Simplified Portion Size Selection Task

Portion size is an important determinant of energy intake and the development of easy to use and valid tools for measuring portion size are required. Standard measures, such as ad libitum designs and currently available computerized portion selection tasks (PSTs), have several limitations including only being able to capture responses to a limited number of foods, requiring participants’ physical presence and logistical/technical demands. The objective of the current study was to develop and test robust and valid measures of portion size that can be readily prepared by researchers and be reliably utilized for remote online data collection. We developed and tested two simplified PSTs that could be utilized online: (1) portion size images presented simultaneously along a horizontal continuum slider and (2) multiple-choice images presented vertically. One hundred and fifty participants (M = 21.35 years old) completed both simplified PSTs, a standard computerized PST and a series of questionnaires of variables associated with portion size (e.g., hunger, food item characteristics, Three Factor Eating Questionnaire). We found average liking of foods was a significant predictor of all three tasks and cognitive restraint also predicted the two simplified PSTs. We also found significant agreement between the standard PST and estimated portion sizes derived from the simplified PSTs when accounting for average liking. Overall, we show that simplified versions of the standard PST can be used online as an analogue of estimating ideal portion size.

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.

Evaluation of Some Ingredients and Energy Content on Front-of-Pack Cereal Bar Labeling as Drivers of Choice and Perception of Healthiness: A Case Study with Exercisers

The objective of this study was to explore the drivers of choice and perceptions of healthiness that specific ingredient or energy content information displayed on the front-of-pack label of cereal bars triggers among different groups of consumers. The participants (18 to 50 years old), classified as exercisers (n = 103, 52 women) or nonexercisers (n = 101, 51 women), completed a questionnaire and then rated their interest using images of cereal bars that varied in four characteristics ("With fruit," "With chocolate," "High protein," and calorie content). Conjoint analysis showed that the most important motives were associated with the convenience, pleasure/indulgence and liking dimensions, which did not differ between groups. These were followed by two other motives introduced in this study: energy/physical activity and satiety, in which the exercisers showed a distinctively higher level of interest than the nonexercisers. Chocolate and a low calorie content were the outstanding drivers of interest, at similar levels for both groups. A high protein content claim increased the interest of all participants, but more so for exercisers and for men. Fruit had a low impact on interest, which was only significant for women. These results indicate that front-of-pack label information influences choice in a distinctive way for some targeted population groups. PRACTICAL APPLICATION: This study contributes knowledge about the impact that front-of-pack label information about certain ingredients and the energy content has on the motives and drivers for snack choices and perceptions of healthiness. The results contribute interesting results on the behavior of some consumer segments, in particular, exercisers and people involved in fitness activities, who are supposed to have special dietary needs.