Food addiction is a relatively recent conceptualization that describes a special type of problematic eating which is not yet covered by the established eating disorders, e.g., binge eating disorder (BED), bulimia nervosa (BN), or anorexia nervosa (AN) (Gearhardt et al.,
2009a). Food addiction posits that highly processed foods, with added fats and/or refined carbohydrates, (e.g., chocolate, biscuits) may be capable of triggering an addictive-like response on a substance-based perspective in some individuals, whereby an interaction with individual susceptibilities plays an important role (Gearhardt, Davis, Kuschner, & Brownell,
2011; Schulte, Avena, & Gearhardt,
2015). Food addiction is commonly assessed by the Yale Food Addiction Scale (YFAS; Gearhardt, Corbin, & Brownell,
2009b,
2016), which applies the substance-related and addictive criteria of the Diagnostic and Statistical Manual of Mental Disorders (DSM; American Psychiatric Association,
1998,
2013) to abnormal patterns of food intake. Defining specific patterns of eating as a food addiction may offer new insights that can inform the development of therapeutic interventions for individuals struggling with their eating behavior. Nevertheless, the research examining the concept of food addiction remains controversial with regards to evidence that can inform precise definitions that quantify the clinical significance of a food addiction diagnosis (Meule & Kübler,
2012; Ziauddeen, Farooqi, & Fletcher,
2012b,
2012a; Ziauddeen & Fletcher,
2013). For example, there are uncertainties in neurobiological evidence, animal research, and inconsistencies in human research on food addiction (Ziauddeen & Fletcher,
2013). Furthermore it is unclear whether food addiction is an independent disorder or part of an already existing disorder, (e.g., BED, BN or AN) (Hauck, Weiß, & Ellrott,
2016).
In a representative sample of the German population, the overall prevalence rate of food addiction was 7.9% (Hauck, Weiß, Schulte, Meule, & Ellrott,
2017). This is similar to rates of approximately 5%–10% of individuals exhibiting symptoms of food addiction in community-based samples (Meule & Gearhardt,
2014). However, higher prevalence rates among obese patients (15%–25%) and individuals with morbid obesity, BED, or BN have been reported (Meule & Gearhardt,
2014). The relationship between weight status and food addiction is complex. That is to say, a substantial portion of underweight and normal weight subjects may also meet food addiction criteria (Corwin & Hayes,
2014; Hauck et al.,
2017; Schulte & Gearhardt,
2017). For example, 15% of underweight individuals report symptoms reflecting food addiction; and this prevalence is similar to those reported in obese samples (Hauck et al.,
2017). Thus, further examination of normal and underweight individuals is needed.