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Internal Reliability Analysis of The Turkish Version of The Yale Food Addiction Scale

Yale Yeme Bağımlılığı Ölçeğinin Türkçe Versiyonunun İç Güvenilirlik Analizi

Esra Senguzel, Serdar Oztora, Hamdi Nezih Dagdeviren


How to cite / Atıf için: Senguzel E, Oztora S, Dagdeviren HN. Internal Reliability Analysis of The Turkish Version of The Yale Food Addiction Scale. Euras J Fam Med 2018;7(1):14-18


Original Research / Orijinal Araştırma


Aim: The aim of this study is to measure the internal reliability of the Turkish version of “Yale Food Addiction Scale Version 2.0” originally developed by Gearhardt et al.

Methods: A total of 51 randomly selected patients between the ages of 18-64 years who applied to Trakya University Family Medicine Outpatient Clinics between 15.12.2016 and 15.01.2017 gave consent and were included in the study. First, “Yale Food Addiction Scale Version 2.0” was translated from English to Turkish. Then, 35-item Yale Food Addiction Scale and a sociodemographic form were applied to participants.

Results: Thirty-five female and sixteen male participants had a mean age of 25.1±7.6 years. A measure of internal reliability, Cronbach’s alfa was found to be 0.875.

Conclusion: Analysis of this study showed the Turkish version of the Yale Food Addiction Scale had a high internal reliability.

Keywords: reliability, feeding and eating disorders, obesity


Amaç: Bu çalışmada Gearhardt ve arkadaşları tarafından geliştirilmiş olan "Yale Food Addiction Scale Version 2.0" ölçeğinin Türkçe versiyonunun iç güvenilirlik analizinin yapılması amaçlanmıştır.

Yöntem: Çalışmaya 15 Aralık 2016-15 Ocak 2017 tarihleri arasında Trakya Üniversitesi Tıp Fakültesi Aile Hekimliği Polikliniği’ne başvuran, çalışmaya katılmaya gönüllü, rastgele seçilmiş, 18-64 yaş arası, toplam 51 hasta dahil edilmiştir. "Yale Food Addiction Scale Version 2.0" ölçeğinin çevirilerinin yapılmasının ardından hazırlanan sosyodemografik form ve 35 soruluk Yale Yeme Bağımlılığı Ölçeği katılımcılara uygulanmıştır.

Bulgular: 35’i kadın 16’sı erkek olan katılımcıların yaş ortalaması 25,1±7,6 olarak saptandı. Ölçeğin iç güvenilirlik katsayısı Cronbach’s alfa 0,875 bulundu.

Sonuç: Bu çalışmada yapılan analiz sonucunda Yale Yeme Bağımlılığı Ölçeği’nin iç güvenilirliğinin yeterince yüksek olduğu gösterilmiştir. 

Anahtar kelimeler: güvenilirlilik, beslenme ve yeme bozuklukları, obezite


Obesity is an increasingly frequent universal health problem that causes morbidity and mortality, affecting the duration and quality of life. As defined by the World Health Organization (WHO), obesity and excess weight are the excessive and abnormal accumulation of the fat tissue which may affect health badly. Body Mass Index (BMI) obtained by dividing weight in kilograms by height in meters squared is used for diagnosis and classification of obesity. According to WHO, BMI equivalent to 25 or greater is considered overweight and 30 or greater is considered as obesity.

The World Health Organization estimates that in 2030, 57.8% of the world population will be in the obesity class (BMI ≥30) or in overweight class (BMI of 25-30) (1). Obesity has some significant psychological, social and economic consequences; also affects country economies with health expenditures related to obesity. In United States of America, obese individuals alone cause 42% more healthcare costs than normal-weight individuals. Statistics show obesity is the second most common preventable cause of death (2). This is the same for Turkey. TURDEP-I (1997-1998) study showed only 57% of the subjects were BMI≥25; while in TURDEP-II (2010) study, this number raised to 72.9% (3).

Since obesity is a complex etiologic condition and there is a great variability in treatment success rates; we cannot mention just one medication or a treatment plan suitable for everyone. Fifty-six percent of the patients who follow a diet program with a high success rate had relapse (1). Twenty to forty percent of the patients who undergo bariatric surgery which is commonly accepted to be highly successful in morbid obesity cannot lose enough weight, some of them gain back weight and some face with complications and comorbidities during and after surgery (2). We need new approaches to prevent and to treat obesity, the disease of the twenty-first century. Pathophysiologic and neurobehavioral mechanisms need to be known to avert risky behaviors, detect individuals under risk and develop new modalities for diagnosis and treatment.

Another common problem in this century is addiction. It affects the personal, social and professional functions and overall life of the individual and family. Along with smoking and alcohol, drug abuse is becoming more and more frequent among young individuals. Also, the gift of modern era, the internet addiction and pathological gambling are seen often among the young adults.  Food addiction which suggests that foods lead to addictive behaviors similar in substance addiction is a new term that has come to fore in recent years and it is proved to have an important role in understanding obesity and solving it. It has been argued to be put in DSM-V, however, it was not, as the factors contributing to development of this addictive behaviors have not been recognized clearly (4). Research on the subject will contribute to understanding of the concept of food addiction.

The judgment of addiction contributing to excessive food consumption is supported by biological, psychological and behavioral similarities. There are neurology studies showing similarities between consumption of certain food types and other forms of addiction (1). Many clinical and preclinical studies showed craving, loss of control and tolerance for food which are the key criteria for addiction (5). Some researchers propose that everyone needs nutrients to survive, not every food leads to addictive behavior and it is not appropriate to define food as addictive substances (5). At this point; salt, fat and sugar-rich foods that contribute to addiction are mentioned in literature. With the development of food industry and marketing; foods that is easily accessible, ‘extremely tasty’, rich in calories, fat, sugar and additives and has increased rewarding features but low in nutrient density have addictive potential. Animal studies show consumption of these foods activate the brain reward system by increasing dopamine release which reinforces eating behavior (5).

Yale Food Addiction Scale (YFAS) was developed and published to identify food addiction by Ashley Gearhardt et al. in 2009 (6). The 27-item self-report YFAS developed in order to determine the dependence on high fat and sugar food that cause symptoms of substance dependence was created by modifying seven symptoms of substance dependency in DSM-IV to food addiction. Subsequently, the scale was updated (YFAS Version 2.0) according to “Substance-Related and Addictive Disorders” criteria in DSM-V and published as a 35-item measure in 2016 (7). Dependency criteria questioned in the scale are shown in Table 1.

In addition to eleven criteria of addictive disorders in DSM-V, questions number 16 and 17 in "YFAS Version 2.0" examine clinically significant impairment or distress (7).

Not all eating behaviors in obesity can be explained by the concept of food addiction; however, it is important that neurobiological changes in addiction are seen in obese individuals (5). Along with genetic and biological processes, unhealthy environmental factors increase the risk of obesity for individuals with sensitive or abnormally developed reward system. Studies show obesity and food addiction to be different terms since food addiction can be seen in individuals with normal body weight or even low BMI; therefore, food addiction alone cannot explain the epidemiology of obesity (1). However, it may be one of the factors and learning more about this factor will contribute to treatment of obesity.

Table 1. The criteria in the scale (7)

This study aims to test the internal reliability of the Turkish version of “Yale Food Addiction Scale Version 2.0” originally developed by Gearhardt et al.


The sample of this study is 51 randomly selected patients between the ages of 18-64 who applied to Trakya University Family Medicine Outpatient Clinics between 15.12.2016 and 15.01.2017 and gave consent to be in the study. Participants who did not volunteer to answer the questions were excluded from the study.

For internal reliability analysis of the Turkish version, original version of the scale was obtained from Ashley Gearhardt. We also got approval from Scientific Researches Ethics Committee of Trakya University Medical Faculty. After “YFAS Version 2.0” was translated from English to Turkish, participants were informed and asked to complete a sociodemographic form and 35-item Yale Food Addiction Scale.

The obtained data were evaluated with SPSS program, internal reliability analysis were performed and Cronbach’s alpha was calculated.


With thirty-five female and sixteen male participants, 51 participants had a mean age of 25.1±7.6 years. Minimum age was 18 and maximum was 56 years. Based on the height and weight reported by the participants, mean BMI was calculated as 23.52±3.97 kg/m². The minimum BMI was 17.10 kg/m² and maximum was 39.89 kg/m². Categorized BMI data are shown in Figure 1 along with percentages.

Figure 1. Categorized BMI data

Measure of internal reliability, Cronbach’s alpha coefficient of the 35-item scale was calculated as 0.875. Cronbach’s alpha coefficients for each item excluded individually are shown in Table 2.


Reliability is defined as the consistency or reproducibility of the results under the same conditions; validity is defined as the appropriateness and adequacy of the interpretations of the measurements (8).

Cronbach’s alpha or alpha coefficient (α), Kuder-Richardson Formula 20 (KR-20) and Hoyt’s analysis of variance are commonly used in reliability studies. Compared to others, Cronbach’s alpha is used more often. While KR-20 is only used for bivalent (0-1 type) data, Cronbach’s alpha is used both for bivalent (0-1 type) and weighted (1, 2, 3, 4, 5 / likert type) data. When all the items are measured in two values (0-1 type), the KR-20 and Cronbach’s alpha show the same results (8).

KR-20 value was found 0.90 and 0.92 respectively in the study of Gearhardt et al (7). A study conducted in France showed the KR-20 value for YFAS 2.0 to be 0.83 which concludes update of the scale according to DSM-V increased its internal consistency (9). While Cronbach’s alpha coefficient was found to be 0.90 in a study conducted in Germany on university students; another study showed alpha coefficient of 0.87 on bariatric surgery candidates (10). It was also thought that lowering diagnostic threshold after DSM-V update would provide higher sensitivity but reduce specificity (10). Our study showed the alpha coefficient to be 0.875 which is similar to other studies conducted in different countries.

There are some limitations to our study such as the use self-report questionnaires and self-reported height and weight data. The sample of our study was randomly selected participants. More extensive research done in the future will contribute to clarification of this subject.

This study on internal reliability of the Turkish version of YFAS 2.0 provides an opportunity to examine the concept of food addiction and its related factors, identify diagnosis and treatment methods, minimize the possible bad outcomes of food addiction and design public health policies accordingly.

Table 2. Cronbach’s alpha coefficient obtained when each question is excluded


In our study, internal reliability analysis of the Turkish version of “Yale Food Addiction Scale Version 2.0” was performed and Cronbach’s alfa was found to be 0.875. This value of Cronbach’s alpha shows a high degree of internal reliability. The results of our study is similar to the results of different internal reliability analysis studies in different samples.

Yale Food Addiction Scale is a tool used for diagnosis and classification of food addiction which is a new term trying to be illuminated.  More studies on this subject will be beneficial to comprehend food addiction, its causes, complications and unknowns.


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