Title: Food Addiction
Description: In recent years, food addiction has become a popular construct believed to have serious behavioral, emotional and physical consequences. However, its scientific validity is still under investigation. This dissertation evaluated whether food addiction is a valid mental disorder, substance-related disorder, and addiction in three parts. Part 1 reviewed the phenomenological, animal and neurological evidence to assess whether food addiction has face validity and conducted a systematic literature review of studies estimating the prevalence, validating measures, and/or assessing correlates of human food addiction to evaluate construct validity. Part 2 used two community-based convenience samples to assess whether operationalized measures of food addiction are reliable and valid. Part 3 used two large cohorts of nurses to evaluate whether food addiction is associated with potentially positively reinforcing nutrients, food items and food groups. The literature review established that food addiction has face validity, and to some degree, construct validity.

The first analytic paper found that the internal and test-retest reliabilities of both scales were moderate to good, and the shorter Modified Yale Food Addiction Scale compared with the original Yale Food Addiction Scale had good sensitivity and negative predictive value. The second analytic paper found strong positive associations between food addiction and consumption of fats and sodium, non-sweet fatty foods, diet foods, and some salty and sweet foods, no association with most starchy and salty food items, and an inverse association with fruits and vegetables. It also found unexpected strong inverse associations between sugar and food addiction, contradicting the popular “sugar addiction” hypothesis. Prospective analyses should reexamine these findings to eliminate potential reverse causation bias. Taken together, this dissertation supported food addiction as a valid mental disorder, substance-related disorder and addiction, although some findings contradicted a priori hypotheses, and gaps in the literature remain.