Individual differences and food-cue reactivity: Predictors of BMI, portion size, and everyday dietary behaviour.

Lead Research Organisation: University of Bristol
Department Name: Experimental Psychology

Abstract

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

Publications

10 25 50
publication icon
Ferriday D (2008) How does food-cue exposure lead to larger meal sizes? in The British journal of nutrition

publication icon
Ferriday D (2008) How does food-cue exposure lead to overeating? in Appetite

publication icon
Ferriday D (2011) 'I just can't help myself': effects of food-cue exposure in overweight and lean individuals. in International journal of obesity (2005)

 
Description 1. Background

People are exposed to the sight and smell of food, often many times a day. Previous research has shown that this 'food-cue exposure' can have a dramatic effect on our appetite. Indeed, in both humans and animals, cue exposure is found to generate a desire to consume the cued food, even in the absence of general hunger. In humans, the specific effects of food-cue exposure have received relatively little attention, and the prospect that individuals differ in their responsiveness to food cues has barely begun to be considered. However this could be extremely relevant, because reactivity to food cues could be an important predictor of overeating and body-weight gain.

2. Project objectives

Objective 1. To determine whether individual differences in food-cue reactivity represents an important risk factor for increased BMI.

Objective 2. To explore specific consequences of cue exposure and to elucidate the process by which cue exposure comes to influence subsequent meal size.

Objective 3. To develop an understanding of how individual differences in food-cue reactivity (as observed in the laboratory) might be related to everyday dietary decisions, and in particular, decisions about portion size.

3. Main research results

A period of pilot testing enabled the PI to develop a set of measures that inform our understanding of decisions about portion size. Briefly, a library of food images was produced. Individual foods were photographed many times in different portion sizes. Using custom-written code, a computer was used to obtain measures of ideal portion size (both typical and momentary), and a measure of the maximum portion size that a person would tolerate.

Two studies were completed. The first of these explored the process by which cue exposure promotes over-consumption of food (objective 2). Three hypotheses were explored; cue exposure i) increases the planned consumption of food, ii) increases tolerance of larger portion sizes, and iii) arrests the development of satiety. Female participants (N=50) were each tested in two conditions. In a 'cue condition' they were exposed to the sight and smell of pizza for 60 seconds. Cueing had little effect on tolerance of larger portion sizes. Instead, it increased prospective pizza-portion size and subsequent intake of pizza. Together, these results are the first of their kind to show that cueing increases the amount of food that people actively plan to eat. Pizza cueing also increased prospective portion size of other foods. Thus, contrary to previous reports, the effects of cue-exposure are more general than anticipated.

In the second study we explored whether these effects of cue exposure are more evident in a group of overweight participants (objective 1). Following a participant recruitment campaign, a participant database was developed involving staff members at the University of Bristol. From this (450 staff), we selected groups of 52 age-matched overweight and normal-weight participants. Participants were tested in a single test session, during which they were exposed to the sight and smell of pizza. The same measures were taken as in Experiment 1, again, both before and after the exposure. However, this study also included a measure of the everyday portion sizes that the participants typically consumed (objective 3). Measures were obtained for a variety of different commonly consumed foods. Finally, a measure of saliva volume was also taken, both before and after cue-exposure. This is important, because it provides and indication of changes in an individual's physiological preparedness to consume food.

The results from this second study confirmed the original hypothesis. Overweight individuals were more cue-reactive, both in terms of the effects of cueing on desire to consume food and in their physiological responsiveness to food cues (salivation). Importantly, we also found that overweight individuals plan to consume larger meals following cueing. However, we failed to find evidence that the overweight group consume larger meals outside the laboratory, or that a measure of their everyday meal size is related to the degree of cue reactivity that they experienced during testing.
Exploitation Route The most important achievement is the successful demonstration of differences in the effects of food-cue exposure on meal size in overweight and normal-weight individuals. This difference has not been reported previously and it raises interesting questions about the effects of cue exposure outside the laboratory. For example, it would be interesting to explore everyday effects of cue exposure in vulnerable populations such as children.

A second achievement relates to the development of new empirical methods. The PI and research associate were able to develop new psychophysical measures that help to shed light on decisions about food and food portions. These methods were used in both studies in this project. However, they are also now being used in other research projects, both in the PI's laboratory and by other external collaborators.
Sectors Agriculture, Food and Drink

 
Description No immediate impact on policy. However, the findings from this research have the potential to inform our understanding of the consequences of exposure to food advertisements and the sight and smell of foods in environments such as hospitals, schools, and the workplace. Currently, we are working on a BBSRC project (BB/J005622/1) exploring ways in which oral processing of food influences satiety and food intake. This work draws on fundamental observations that were made as part of this ESRC-funded project.
First Year Of Impact 2007
 
Description BBC Radio 4 Food Programme 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Participation in radio broadcast which sparked discussion about food cravings and preferences.

Increased public awareness regarding the factors which contribute to food choice.
Year(s) Of Engagement Activity 2012
URL http://www.bbc.co.uk/programmes/p00yyr41
 
Description Media interest (Portion size, expected satiety, and the role of dietary variability) 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Current research projects were highlighted on BBSRC website.

Web coverage of our projects highlighted our current lines of research, attracting new interest in our research team.
Year(s) Of Engagement Activity 2013
URL http://www.bbsrc.ac.uk/news/health/2013/130204-f-would-you-like-to-supersize-that.aspx
 
Description Response to Reuters media request 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Dr Danielle Ferriday responded to a media request from Reuters and an article was published based on these responses.

This article disseminated the findings and was picked up by other major news outlets.
Year(s) Of Engagement Activity 2010
URL http://in.reuters.com/article/2010/07/21/us-overweight-meal-idINTRE66K3OL20100721