Ashley N. Gearhardt

Can food be addictive? Public health and policy implications.

AIMS Data suggest that hyperpalatable foods may be capable of triggering an addictive process. Although the addictive potential of foods continues to be debated, important lessons learned in reducing the health and economic consequences of drug addiction may be especially useful in combating food-related problems. METHODS In the current paper, we review the potential application of policy and public health approaches that have been effective in reducing the impact of addictive substances to food-related problems. RESULTS Corporate responsibility, public health approaches, environmental change and global efforts all warrant strong consideration in reducing obesity and diet-related disease. CONCLUSIONS Although there exist important differences between foods and addictive drugs, ignoring analogous neural and behavioral effects of foods and drugs of abuse may result in increased food-related disease and associated social and economic burdens. Public health interventions that have been effective in reducing the impact of addictive drugs may have a role in targeting obesity and related diseases.

Food addiction: an examination of the diagnostic criteria for dependence.

The evidence for food’s addictive properties is steadily growing. In addition to clinical and evolutionary plausibility, the possibility of addiction to food is supported by animal model research and increasingly by research with humans. Much as classic drugs of abuse “hijack” the brain, accumulating evidence with food suggests a similar impact, but with weaker effects. Although neurobiological evidence for food addiction is compelling, dependence as conceptualized with respect to alcohol and other drugs of abuse is fundamentally a behavioral disorder. Thus, we review the current state of food addiction research in the context of each of the diagnostic criterion for dependence (ie, tolerance, withdrawal, loss of control) and briefly explore other relevant addiction topics such as expectancies, reinforcement, and incentive salience. There is substantial evidence that some people lose control over their food consumption, suffer from repeated failed attempts to reduce their intake, and are unable to abstain from certain types of food or reduce consumption in the face of negative consequences. Although there is some evidence for other dependence criterion, further research is needed to examine tolerance and withdrawal to high-fat sweets, time spent in obtaining, using, and recovering from excess food consumption and the degree to which important activities are given up due to overconsumption. As science continues forward and both the public and elected leaders become aware that food may trigger an addictive process, this information will likely be used to inform policy. Thus, researchers need to carefully consider the implications of their work and the way in which the results may be interpreted.

The prevalence of food addiction as assessed by the Yale Food Addiction Scale: a systematic review.

Obesity is a global issue and it has been suggested that an addiction to certain foods could be a factor contributing to overeating and subsequent obesity. Only one tool, the Yale Food Addiction Scale (YFAS) has been developed to specifically assess food addiction. This review aimed to determine the prevalence of food addiction diagnosis and symptom scores, as assessed by the YFAS. Published studies to July 2014 were included if they reported the YFAS diagnosis or symptom score and were published in the English language. Twenty-five studies were identified including a total of 196,211 predominantly female, overweight/obese participants (60%). Using meta-analysis, the weighted mean prevalence of YFAS food addiction diagnosis was 19.9%. Food addiction (FA) diagnosis was found to be higher in adults aged >35 years, females, and overweight/obese participants. Additionally, YFAS diagnosis and symptom score was higher in clinical samples compared to non-clinical counterparts. YFAS outcomes were related to a range of other eating behavior measures and anthropometrics. Further research is required to explore YFAS outcomes across a broader spectrum of ages, other types of eating disorders and in conjunction with weight loss interventions to confirm the efficacy of the tool to assess for the presence of FA.

Which Foods May Be Addictive? The Roles of Processing, Fat Content, and Glycemic Load

Objectives We propose that highly processed foods share pharmacokinetic properties (e.g. concentrated dose, rapid rate of absorption) with drugs of abuse, due to the addition of fat and/or refined carbohydrates and the rapid rate the refined carbohydrates are absorbed into the system, indicated by glycemic load (GL). The current study provides preliminary evidence for the foods and food attributes implicated in addictive-like eating. Design Cross-sectional. Setting University (Study One) and community (Study Two). Participants 120 undergraduates participated in Study One and 384 participants recruited through Amazon MTurk participated in Study Two. Measurements In Study One, participants (n = 120) completed the Yale Food Addiction Scale (YFAS) followed by a forced-choice task to indicate which foods, out of 35 foods varying in nutritional composition, were most associated with addictive-like eating behaviors. Using the same 35 foods, Study Two utilized hierarchical linear modeling to investigate which food attributes (e.g., fat grams) were related to addictive-like eating behavior (at level one) and explored the influence of individual differences for this association (at level two). Results In Study One, processed foods, higher in fat and GL, were most frequently associated with addictive-like eating behaviors. In Study Two, processing was a large, positive predictor for whether a food was associated with problematic, addictive-like eating behaviors. BMI and YFAS symptom count were small-to-moderate, positive predictors for this association. In a separate model, fat and GL were large, positive predictors of problematic food ratings. YFAS symptom count was a small, positive predictor of the relationship between GL and food ratings. Conclusion The current study provides preliminary evidence that not all foods are equally implicated in addictive-like eating behavior, and highly processed foods, which may share characteristics with drugs of abuse (e.g. high dose, rapid rate of absorption) appear to be particularly associated with “food addiction.”

An examination of food addiction in a racially diverse sample of obese patients with binge eating disorder in primary care settings

OBJECTIVE The concept of food addiction in obesity and binge eating disorder (BED) continues to be a hotly debated topic yet the empirical evidence on the relationship between addictive-like eating and clinically relevant eating disorders is limited. The current study examined the association of food addiction as assessed by the Yale Food Addiction Scale (YFAS) with measures of disordered eating, dieting/weight history, and related psychopathology in a racially diverse sample of obese patients with binge eating disorder (BED). METHOD A consecutive series of 96 obese patients with BED who were seeking treatment for obesity and binge eating in primary care were given structured interviews to assess psychiatric disorders and eating disorder psychopathology and a battery of self-report measures including the YFAS to assess food addiction. RESULTS Classification of food addiction was met by 41.5% (n=39) of BED patients. Patients classified as meeting YFAS food addiction criteria had significantly higher levels of negative affect, emotion dysregulation, and eating disorder psychopathology, and lower self-esteem. Higher scores on the YFAS were related to an earlier age of first being overweight and dieting onset. YFAS scores were also significant predictors of binge eating frequency above and beyond other measures. DISCUSSION Compared to patients not classified as having food addiction, the subset of 41.5% of BED patients who met the YFAS food addiction cut-off appears to have a more severe presentation of BED and more associated pathology.

Development of the Yale Food Addiction Scale Version 2.0.

Parallels in biological, psychological, and behavioral systems have led to the hypothesis that an addictive process may contribute to problematic eating. The Yale Food Addiction Scale (YFAS) was developed to provide a validated measure of addictive-like eating behavior based upon the diagnostic criteria for substance dependence. Recently, the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) was released, which included significant changes to the substance-related and addictive disorders (SRAD) section. In the current study, the YFAS 2.0 was developed to maintain consistency with the current diagnostic understanding of addiction and to improve the psychometric properties of the original YFAS. In a sample of 550 participants, 14.6% met criteria for food addiction. The YFAS 2.0 demonstrated good internal consistency, as well as convergent, discriminant, and incremental validity. Elevated scores on the YFAS 2.0 were associated with higher rates of obesity and more severe pathological eating (e.g., binge eating). The YFAS 2.0 also appeared to capture a related, but unique construct relative to traditional eating disorders. In a separate sample of 209 participants, the YFAS and YFAS 2.0 were directly compared. Both versions of the YFAS were similarly associated with elevated body mass index, binge eating, and weight cycling. However, exceeding the food addiction threshold was more strongly associated with obesity for the YFAS 2.0 than the original YFAS. Thus, the YFAS 2.0 appears to by a psychometrically sound measure that reflects the current diagnostic understanding of addiction to further investigate the potential role of an addictive process in problematic eating behavior.

Tossing the baby out with the bathwater after a brief rinse? The potential downside of dismissing food addiction based on limited data

A recent Perspective article that provided a critical analysis of the food addiction model as it relates to obesity stated that the model is “misleading”, with supporting evidence described as “inconsistent and weak” (Obesity and the brain: how convincing is the addiction model? Nature Rev. Neurosci. 13, 279–286 (2012))1. Whether non-drug-related addictions exist has been debated, with recent proposals for the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) giving the concept greater credence2, 3, 4. The timely article by Ziauddeen et al.1 raised important points, including differences in findings across studies of obesity. Although we agree that not all obese individuals exhibit food addiction, we believe it is premature to reject the concept of food addiction. The extent to which food addiction applies to individuals with obesity, or subgroups thereof, deserves further research, particularly as such studies may help to better define clinically relevant subgroups who respond differently to specific prevention and treatment strategies5. Rejection of a model on the basis of limited data could be deleterious.

Food-addiction scale measurement in 2 cohorts of middle-aged and older women

BACKGROUND Excess weight is a major threat to public health. An addiction-like tendency toward certain foods may contribute to overeating. OBJECTIVE We aimed to describe the prevalence and associated characteristics in relation to a food-addiction scale in middle-aged and older women. DESIGN We examined the prevalence and associated characteristics of a food-addiction scale measure in a cross-sectional analysis of 134,175 women participating in 2 ongoing prospective cohort studies of US nurses. RESULTS Overall, 7839 (5.8%) of the women surveyed met the criteria for food addiction measured by using the modified Yale Food Addiction Scale. The prevalence of food addiction was 8.4% in the younger cohort of women aged 45-64 y and 2.7% in the older cohort of women aged 62-88 y. In the multivariate model, body mass index (BMI; in kg/m²) ≥ 35.0 (compared with 18.5-22.9) was associated with food addiction, a prevalence ratio (PR) of 15.83 (95% CI: 12.58, 19.91) in the younger cohort of women, and a PR of 18.41 (95% CI: 11.63, 29.14) in the older cohort of women. Several other demographic characteristics and other factors were associated with the food-addiction measure in both cohorts of women. CONCLUSIONS To our knowledge, for the first time in a large, US-based population of women, we documented the prevalence of food addiction by using a novel measurement scale in middle-aged and older women. The results may provide insight into the strong association between behavioral attributes of food consumption and the development of obesity.

Relation of Obesity to Neural Activation in Response to Food Commercials

Adolescents view thousands of food commercials annually, but the neural response to food advertising and its association with obesity is largely unknown. This study is the first to examine how neural response to food commercials differs from other stimuli (e.g. non-food commercials and television show) and to explore how this response may differ by weight status. The blood oxygen level-dependent functional magnetic resonance imaging activation was measured in 30 adolescents ranging from lean to obese in response to food and non-food commercials imbedded in a television show. Adolescents exhibited greater activation in regions implicated in visual processing (e.g. occipital gyrus), attention (e.g. parietal lobes), cognition (e.g. temporal gyrus and posterior cerebellar lobe), movement (e.g. anterior cerebellar cortex), somatosensory response (e.g. postcentral gyrus) and reward [e.g. orbitofrontal cortex and anterior cingulate cortex (ACC)] during food commercials. Obese participants exhibited less activation during food relative to non-food commercials in neural regions implicated in visual processing (e.g. cuneus), attention (e.g. posterior cerebellar lobe), reward (e.g. ventromedial prefrontal cortex and ACC) and salience detection (e.g. precuneus). Obese participants did exhibit greater activation in a region implicated in semantic control (e.g. medial temporal gyrus). These findings may inform current policy debates regarding the impact of food advertising to minors.

Five years of the Yale Food Addiction Scale: Taking stock and moving forward

Some forms of overeating show both behavioral and neurobiological similarities to substance use disorders. Accordingly, a possible addiction to food has been discussed for decades, and the debate has received increased scientific and public attention since the beginning of the twenty-first century. In 2009, the Yale Food Addiction Scale (YFAS) was developed in an attempt to provide a standardized self-report instrument for the assessment of food addiction based on the diagnostic criteria for substance dependence. Since then, the YFAS has been used in numerous studies and celebrates its fifth anniversary this year. This article presents an overview of the YFAS and its adaptations, which includes a detailed description of scoring instructions and a supplementary SPSS syntax. Furthermore, psychometric properties and correlates of the YFAS, as well as prevalence rates of food addiction diagnoses and symptoms in different populations, are reviewed. Finally, shortcomings of the scale and future directions for food addiction research and revisions of the YFAS are discussed.