European research grant helps to map behavioural causes of weight change variability with genetic lottery
Uku Vainik, Associate Professor of Behavioural Genetics at the University of Tartu, has been awarded a Starting Grant from the European Research Council (ERC) to study the behavioural and genetic links to obesity and to identify possible new interventions to combat obesity.
Obesity is a hereditary chronic disease affecting nearly one billion people worldwide. According to the World Health Organization, by 2030, just over half of the human population will be overweight or obese. Given the health problems that accompany obesity, this is a huge additional burden on healthcare systems and requires rapid and effective solutions.
A wide range of treatments, from behavioural recommendations and medication to gastric bypass surgery, have been developed to combat overweight and obesity. However, the interventions have very different effects on people struggling with weight. Some can overcome their weight problem, while others regain the extra weight despite their best efforts.
Vainik's research team is trying to understand what factors might be more broadly predictive of weight loss, whether they have a causal relationship with weight loss success, and whether weight loss programmes can be made more effective by understanding this relationship. In their research, they use machine learning, health data collected in gene banks and a mobile app that supports health behaviour.
Machine learning helps to clarify information overload
Nearly 200 factors have been proposed in the scientific literature as predictors of weight loss success, including psychosocial, environmental, behavioural and biological factors and those related to quality of life. However, there are too many of these to measure in a single person. Vainik plans to aggregate these factors in large datasets using machine learning and reduce the heterogeneity in the wording of the same indicator. For example, in the case of personality traits, good self-control, fortitude, conscientiousness and perseverance may mean essentially the same thing.
Similar factors can be aggregated in datasets where weight change factors have been measured over time. For example, over the years, gene donors in the Estonian Biobank have helpfully participated in several studies covering most of the 200 weight change factors. Data from the studies and medical check-ups also provide a history of people's weight, allowing researchers to match weight changes with the factors that may have influenced them. "In Estonia, over the last decade, a few thousand people have used prescribed medication or surgery to lose weight. However, tens of thousands of people have experienced weight loss or gain without guidance from the doctor. The data from the recent personality study and the wellbeing and mental health study of the biobank will allow us to combine physical health information with mental health and personality data, and to look for possible behavioural factors that may influence weight change,” explained Vainik.
Causal link between weight change and its predictors
The identified relationships are tested against datasets from Germany, the UK and Sweden to find similar characteristics. The aim is to create a questionnaire to identify the bottlenecks in weight loss. It should include as wide a range of factors as possible related to weight change that are psychometrically well-measured.
In addition, data from the Estonian Biobank will help to identify causal relationships between weight change predictors and the weight change itself. Genetic information allows us to identify which factors mentioned in the questionnaire actually influence weight loss. "People differ in their genetic likelihood to have higher or lower conscientiousness or faster or slower eating rate. This genetic baggage has been randomly assembled from the genome of our parents, so the human genome mimics a natural experiment. In this way, we can see whether the detected genetic probability to be more conscientious or eat faster also influences the likelihood of weight change success later on. This will help us to identify potentially more effective causal factors of weight change," Vainik explained.
Weight-loss programmes created in partnership with the private sector will be used to verify these effective factors. Users of the programmes will help to confirm whether genetically screened behavioural guidelines for weight loss actually work.
The project starts in 2024, lasts for five years and is funded by the European Research Council with €1.5 million. Researchers from both the Institute of Psychology and the Institute of Genomics of the University of Tartu are involved in the project. The writing of the grant proposal was supported by the Project Writing Unit of the university’s Grant Office, as well as by the university’s ERC Incentive Grant. The grant from the Estonian Research Council helped to prepare for the interviews of the call.
