Obesity has limited behavioural overlap with addiction and psychiatric phenotypes

Obesity is a widespread health condition¹, likely to be driven by the increased availability of inexpensive high-calorie food². People vary greatly in their behavioural response to food. Such variation is likely to be driven by behavioural styles^3,4, as behaviour accounts for overall food intake⁵. A prominent hypothesis is that people with obesity respond to rewards similarly to people with addictions such as alcohol abuse or smoking^6,7. For instance, perceived overeating or 'uncontrolled eating' (UE) is the most common obesity-associated personality trait⁸ and resembles the perceived loss of control seen in drug addiction. Likewise, both obesity and addictive behaviours have similar correlations with broad personality domains³. Here we seek to empirically test whether obesity and UE overlap behaviourally with addiction and psychiatric disorders, collectively referred to as phenotypes. We test for behavioural similarity by linking the personality profiles of each phenotype. NEO Personality Inventory profiles of 28 phenotypes were extracted from 22 studies, encompassing summary statistics from 18,611 unique participants. Obesity had moderate and UE high behavioural similarity with addictions. UE also overlapped behaviourally with most psychiatric phenotypes, whereas obesity was behaviourally similar with mood disorders and certain personality disorders. Facet-based phenotype profiles provided more information than domain-based profiles.