Facial affective reactions to bitter-tasting foods and body mass index in adults

• Published in: Appetite 2013-12, Vol.71, p.178-186
• Main Authors: Garcia-Burgos, D., Zamora, M.C.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Affect; Affective facial reaction; Bitter food; Body Mass Index; Choice Behavior; Energy Intake; Facial Expression; Female; Food Preferences; Humans; Linear Models; Male; Middle Aged; Overweight; Smell; Surveys and Questionnaires; Taste; Taste responsiveness; Young Adult
• ISSN: 0195-6663; 1095-8304
• DOI: 10.1016/j.appet.2013.08.013

•Bitter foods elicited intense disgusted reactions in high BMI participants.•Sensory appeal (taste, smell, appearance) was important for food choices in low BMI.•Incentive ratings revealed that low BMI group wanted to drink more bitter foods.•Bitter taste perception did not correlate with BMI condition. Differences in food consumption among body-weight statuses (e.g., higher fruit intake linked with lower body mass index (BMI) and energy-dense products with higher BMI) has raised the question of why people who are overweight or are at risk of becoming overweight eat differently from thinner people. One explanation, in terms of sensitivity to affective properties of food, suggests that palatability-driven consumption is likely to be an important contributor to food intake, and therefore body weight. Extending this approach to unpalatable tastes, we examined the relationship between aversive reactions to foods and BMI. We hypothesized that people who have a high BMI will show more negative affective reactions to bitter-tasting stimuli, even after controlling for sensory perception differences. Given that hedonic reactions may influence consumption even without conscious feelings of pleasure/displeasure, the facial expressions were included in order to provide more direct access to affective systems than subjective reports. Forty adults (28 females, 12 males) participated voluntarily. Their ages ranged from 18 to 46years (M=24.2, SD=5.8). On the basis of BMI, participants were classified as low BMI (BMI23; n=20). The mean BMI was 19.1 for low BMI (SD=0.7) and 25.2 for high BMI participants (SD=1.8). Each subject tasted 5mL of a grapefruit juice drink and a bitter chocolate drink. Subjects rated the drinks’ hedonic and incentive value, familiarity and bitter intensity immediately after each stimulus presentation. The results indicated that high BMI participants reacted to bitter stimuli showing more profound changes from baseline in neutral and disgust facial expressions compared with low BMI. No differences between groups were detected for the subjective pleasantness and familiarity. The research here is the first to examine how affective facial reactions to bitter food, apart from taste responsiveness, can predict differences in BMI.