My main research topic has been understanding the behavioural roots for obesity and overeating. Behaviour is measured either by personality tests, capturing our typical thoughts, feelings, and behaviours, or cognitive tests characterising our thought processes. I have conducted multiple large-scale data analyses and reviews showing that both personality and cognition have robust links with obesity.

I also seek to test lay theories of behavior with actual data. For instance, obesity has been proposed to have behavioural similarities with addictions, resulting in the concept of food addiction. To test that idea, I developed a method that compares personality profiles of health behaviours. We found that obesity has only limited behavioural similarity with addictions.

My most recent passion is to test the causal role of behaviour in health. Psychologists like to think that personality traits and cognitive abilities cause health behaviours, such as obesity, smoking, or depression. However, these theories have been rarely tested, since randomised controlled trials are expensive. I now seek to utilise genomic causal inference methods, such as Mendelian randomisation and Direction of Causation. We have recently found that against expectations, obesity seems to cause personality traits.

Besides those three topics, I have extensive experience in psychological test development and refinement in the health domain. Most recently, I was been part of US National Institutes of Health effort to choose most promising cognitive tests for obesity and diabetes trials.

As a practical outcome, together with René Mõttus and testmybrain.org, I have developed an optimal set of quick and detailed measures of personality and cognition.