International Weight Control Registry: A Worldwide Repository of Individuals Seeking Weight Loss Management
Submitted to FCT, not yet started
Inês Santos (PI) & Pedro J. Teixeira (Co-PI)
(Public Summary of the Project Submitted in March 9, 2021)
This project is set in the context of obesity, which is a prevalent, persistent, complex, chronic and relapsing disease (1), posing enormous challenges for society in terms of management and care (which have been exacerbated by the current COVID-19 pandemic (2)). Physiological, dynamic changes that occur during weight loss, as well as complex interactions between environmental, behavioral and psychosocial factors seem to undermine the long-term effectiveness of multi-component behavioral interventions aimed at weight management, resulting in low levels of success (3, 4). Therefore, a better understanding of weight loss and maintenance behaviors remains necessary to provide individuals and groups with more effective weight management solutions. In this context, knowing how individuals already successful at long-term weight management are able to lose weight and, especially, maintain it, is critical.
Several weight control registries have been implemented throughout the world to study successful weight loss maintenance (5-9). However, all of them have limitations: The U.S. registry has recruited a large group of participants, but it is not a sufficiently diverse sample, mostly composed of middle-aged, upper income Caucasian women; the European registries recruited small samples and had a limited ability to analyze subgroups. Most of these registries were focused only on successful weight loss maintenance, not addressing the reasons underlying weight loss regain or the characteristics of weight regainers. Finally, little information has been obtained on factors, such as geography, policies, and culture potentially influencing weight control behaviors. A recent systematic review synthesized the difference and similarities between all these registries (10). Fifty-one personal strategies were identified, but it is unknown whether there are patterns across determinants of success which are stable (or comparable) across countries.
As a logical next step, researchers from the U.S., Canada, Europe, the Middle East, South America, and Australia, with expertise in different areas, combined forces to create the International Weight Control Registry. It is a unique, global database, aimed at extending our understanding of the factors involved in weight loss and weight loss maintenance, in particular by also including geography, policies, and cultural factors that may influence weight control behaviors. This project aims to position Portugal within the international registry and expand it by enrolling Portuguese individuals successful and unsuccessful at weight loss maintenance, and also individuals with overweight/obesity interested in losing weight but that have not yet lost significant weight. By enrolling a broad and larger number of participants, we aim to i) identify demographic, behavioral, metabolic, psychosocial, environmental and cultural factors that contribute either to success or failure in attempts to lose and maintain weight; ii) identify subgroups of individuals that respond similarly based on these factors; and iii) follow participants annually in order to identify trajectories in weight-related variables and examine predictors of these trajectories.
To meet these objectives, we seek to recruit a minimum of 850 adults in Portugal, via practitioners (e.g., nutritionists, obesity clinics), social media, targeted online advertisements, and previous weight control programs. At study entry and once every year, participants will complete a web-based survey with questionnaires recommended by the NIH-led ADOPT project (Accumulating Data to Optimally Predict Obesity Treatment) project (11) to assess behavioral, psychological, and social and physical environmental factors. Assessments of nutritional-related factors (dietary intake, anthropometry, body composition, and resting metabolism) and 24h-movement behaviors will also be conducted among two random subsamples of participants (n=100 each). A centralized datahub at Tufts University will accommodate all data collected from all countries, which will allow global data analysis and synthesis but also cross-cultural comparisons.
Our multidisciplinary expertise in the fields of nutrition, human movement sciences, psychology and epidemiology, and the extensive experience in the coordination of many large research projects and the designing and implementation of behavioral change interventions, are vital for the successful execution of this project. Its strengths include the generation of new knowledge on predictors of weight loss maintenance and regain, following a multi-country, multi-cultural approach; the well-established institutions involved (ULHT, FMH, FMUL, IPSantarém, UAB and Tufts); the diverse expertise of the research team, that has a solid publication record and has attracted several European level grants; and the potential public health impact of the topic under analysis, considering the present burden of obesity and its comorbidities on society.