Investigation Method for Exploring Taste Preferences in Anorexia and Bulimia Nervosa: Through a Quasi-Experimental, Cross-Sectional Study to Discern Whether Food Tastes Deterrent or More Pleasurable in Eating Disorders
A groundbreaking study, recently approved by the Swiss ethics committee (CER-VD, n° 2016-02150) and the Ethics Review Panel of the University of Luxembourg, aims to delve into the intricate relationship between taste perception and hedonics in Anorexia Nervosa (AN) and Bulimia Nervosa (BN). The research will explore how altered reward and aversion responses to food significantly contribute to food avoidance in AN and binge-eating episodes in BN.
In AN, individuals often experience reduced pleasure (hedonic response) from food, possibly due to altered taste perception or neurobiological changes affecting reward circuits. This diminished pleasure contributes to food avoidance and restriction, as eating no longer provides normal reward sensations and may even evoke discomfort or anxiety. Physical symptoms related to past malnutrition and slowed gastric motility (like nausea, constipation, and delayed gastric emptying) exacerbate this aversive experience, reinforcing avoidance behaviors.
On the other hand, BN patients may not experience as significant a blunting of taste perception, but they grapple with complex interactions between craving and distress. Episodes of binge eating are often triggered by dysregulated nervous system states, where individuals may seek highly palatable, rewarding foods to self-soothe or regulate negative emotions, leading to intense hedonics during binges. However, this is often followed by guilt and physical distress, reinforcing a vicious cycle of bingeing and purging.
The study will employ the Signal Detection Theory in analyzing taste aversion in eating disorders. It will present four mixtures of sweet-fat stimuli in a sensory two-alternative forced-choice test (Study 1). Additionally, Study 2 will conduct a full-scale taste reactivity test, including psychophysiological and behavioral measures.
The research will compare the responses of currently-ill AN and BN patients to those who have recovered from AN and BN. It also aims to examine whether an increased hedonic valence of sweet, caloric-dense foods may be part of the mechanisms triggering binge-eating episodes in BN. The role of cognitions influencing these mechanisms will be thoroughly examined throughout the study.
The expected results on cognitive mechanisms in the top-down processes of food hedonics will complement current models. If taste response profiles are differentially linked to ED types, the study will investigate whether taste responsiveness represents a useful diagnostic measure in the prevention, assessment, and treatment of EDs. The study will also compare the responses of AN and BN patients to those of healthy normal-weight and underweight individuals without any eating disorder pathology.
The findings from this study could offer valuable insights into the complex interplay between taste perception, hedonics, and eating disorders, potentially leading to more targeted treatment strategies and improved patient outcomes.
[1] Reference for physical symptoms related to past malnutrition and slowed gastric motility [2] Reference for dysregulation in nervous system responses affecting both disorders [4] Reference for neurobiological studies suggesting neuroinflammation and altered brain reward pathways
- Eye tracking can be utilized to examine the food cues that trigger discomfort or anxiety in individuals with Anorexia Nervosa (AN), providing insights into the relationship between taste perception, mental health, and health-and-wellness.
- Similarly, in the context of Fitness-and-Exercise, researchers may investigate the role of altered brain reward pathways in the development and maintenance of overeating or binge-eating episodes in Bulimia Nervosa (BN), as well as the potential for nutrition as a therapeutic intervention to restore normal reward mechanisms.
- Future research in the field of science may also explore the interaction between taste perception, hedonics, and mental health in various health-and-wellness contexts, such as stress management and emotional regulation, to develop multidimensional approaches that support overall well-being and effective treatment strategies.
