Individual differences in food-cue reactivity. The role of BMI and everyday portion-size selections

Abstract

This study sought to explore the association between sensitivity to food cues (sight and smell of food) and (i) body weight (overweight or non-overweight), (ii) typical everyday portion sizes, and (iii) the DEBQ-restraint scale. One hundred and twenty female participants (aged between 18 and 30) were exposed to the sight and smell of pizza for three minutes. Both before and after this period, three measures of food-cue reactivity were taken (ratings of desire to eat, craving, and a measure of desired portion size of the cued food). Separate regression analyses were used to explore the associations between the change in measures of cue reactivity from pre- to post-cue exposure, and (i) an overweight/non-overweight classification, (ii) a measure of participants everyday portion-size selection, and (iii) scores on the DEBQ-restraint scale. This analysis revealed that scores on the DEBQ-restraint scale were not significantly associated with changes in food-cue reactivity. However, individuals identified as overweight, and participants who reported consuming the largest everyday portion sizes, experienced a significantly greater change in their desired portion size of the cued food. The findings suggest that heightened food-cue reactivity might present an under-explored risk factor for overeating, and becoming overweight, and/or maintaining an overweight body shape.

Introduction

The effects of ‘cue reactivity’ in drug-taking behaviour have been explored extensively. Numerous studies show that exposure to a cue such as the sight of a cigarette, or other drug paraphernalia, can elicit both a physiological response (e.g., Breteler, Schippers, De Jong, van der Stark, 2000; Rikard-Figuero & Zeichner, 1985), and a specific craving (e.g., Burton & Tiffany, 1997; Field & Duka, 2005; Pomerlau, Fertig, Baker, & Conney, 1983) that can lead to drug-taking behaviour (e.g., Wigmore & Hinson, 1991).

By contrast, relatively less is known about reactivity to food cues. In animals, exposure to a familiar food is found to elicit feeding behaviour, and this occurs even in the absence of nutritional need (Weingarten, 1985). Similar reactivity to food cues has also been observed in humans. For example, exposure to food cues has been found to stimulate a physiological preparedness to consume food (see Mattes, 1997), evidenced by increases in salivation, heart rate, heart rate variability, blood pressure, skin conductance, and gastric activity (Nederkoorn, Smulders, Havermans, & Jansen, 2004; Nederkoorn, Smulders, & Jansen, 2000). Likewise, exposure to the sensory characteristics of food has been found to stimulate food intake (Cornell, Rodin, & Weingarten, 1989).

Despite basic research investigating food-cue reactivity, relatively few studies have explored individual differences in this dietary phenomenon, and very little is known about the extent to which elevated food-cue reactivity represents a risk factor for behaviours leading to overeating and obesity. In a recent study, Jansen et al. (2003) suggested that sensitivity to food cues might differ in overweight, and non-overweight, children. Yet, to date, this finding has not been confirmed in adults. Rather, previous authors have considered differences in food-cue reactivity across restrained, and unrestrained, eaters. These studies have revealed that restrained eaters consume larger amounts of a cued food than unrestrained eaters (Fedoroff, Polivy, & Herman, 1997; Fedoroff, Herman, & Polivy, 2003; Jansen & van den Hout, 1991; Rogers & Hill, 1989) after food-cue exposure, and experience a greater desire to eat, elevated levels of craving (Fedoroff et al., 1997, Fedoroff et al., 2003), increases in salivation (Brunstrom, Yates, & Witcomb, 2004; Klajner, Herman, Polivy, & Chhabra, 1981) and increased blood pressure (Nederkoorn et al., 2000).

There is reason to suspect that heightened food-cue reactivity in adults might be associated with a more general tendency towards being overweight and daily overeating. Put simply, food-cue reactivity is assumed to represent a form of conditioned response. Thus, after repeated pairing of an external cue with the ingestion of food, mere exposure to the cue is found to initiate appetitive behaviour, even in the absence of prior hunger (Birch, McPhee, Sulivan, & Johnson, 1989; Weingarten, 1984). Given this, one possibility is that individuals who are especially cue reactive may be prone to overeating and being overweight. This is because they are more likely to engage in dietary behaviours that promote a positive energy balance.

Here, our primary objective was to examine whether cue reactivity is associated with being overweight and consuming larger everyday portion sizes. Specifically, we hypothesised (i) that overweight individuals will experience greater reactivity to a food cue than non-overweight individuals and (ii) that individuals who report consuming larger everyday portion sizes will experience greater food-cue reactivity than individuals who typically consume smaller everyday portion sizes.

A secondary aim was to determine the extent to which food-cue reactivity is associated with a tendency to restrict ones dietary intake. As discussed, previous studies have suggested that restrained eaters experience elevated levels of food-cue reactivity (Fedoroff et al., 1997, Fedoroff et al., 2003). However, these studies have assessed dietary restraint using a measure which identifies restrained eaters who engage in dietary restriction interspersed with bouts of disinhibited eating. Accordingly, in this study we sought to determine the extent to which food-cue reactivity is associated with a tendency to restrict ones dietary intake, independently of a tendency to engage in ‘disinhibited eating’ by using the Dutch Eating Behaviour Questionnaire Restraint Scale (DEBQ-R; van Strien, Frijiter, Begers, & Defares, 1986) as a measure of food restriction.

In the present study, we used a version of a paradigm that was introduced by Cornell et al. (1989). Following Weingarten's (1985) notion of ‘cue-induced hunger,’ Cornell et al. (1989) sought to determine the extent to which food-cue exposure induces a motivation to eat in the absence of physiological need. Accordingly, participants were offered a buffet lunch prior to food-cue exposure. Likewise, in the present study, participants were asked to consume items from a buffet lunch until they felt satiated prior to exposure to a food cue.

In previous food-cue reactivity studies (Fedoroff et al., 1997, Fedoroff et al., 2003), food-cue reactivity has been assessed using a measure of intake of a cued food. Typically, in these studies, intake in a ‘control’ (non-cued) condition is compared with intake in a food-cued condition. However, this design is flawed given that even the presentation of food immediately prior to an eating episode acts as a cue to stimulate intake (Weingarten, 1985). Thus, a non-cued condition effectively becomes a cued condition. Consequently, in the present study, a novel measure of desired portion size of the cued food was employed to minimise undesirable cueing effects in the ‘non-cued’ condition. Participants were asked to indicate their desired portion of the test food (pizza) before, and after, exposure to this food using a representation of the food, rather than the actual food. This allowed us to detect changes in prospective intake brought about by exposure to the food cue, and most importantly it minimised cueing effects in the pre-exposure phase.