Experimental approaches
Physical activity
While it is apparent that physical activity has beneficial effects on health and reduces the negative consequences of excess weight, our understanding of its relationship to obesity - and of its mechanisms, effect size, optimal level and effective implementation for prevention or treatment - is limited. Developments in methodology and the use of cohorts are required to increase progress. Like bariatric surgery, physical activity may be a useful experimental tool with which to examine pathways linking obesity and disease.
Ethnicity and obesity
Different ethnic groups vary in susceptibility to obesogenic environments and to the adverse consequences of obesity, for both genetic/physiological and cultural/behavioural reasons. Effective interventions may also depend on the social and cultural context in which they are applied. The study of ethnic differences, and of the impacts of migration on specific population groups, may provide important mechanistic insights into pathways to obesity risk and its adverse consequences. Additionally, information on the propensities of different ethnic groups to obesity and its adverse consequences will be valuable for clinical decision-making.
Bariatric surgery as an experimental model
Bariatric surgery is an effective intervention for obesity and its metabolic consequences but its mechanism of action is poorly understood, particularly why positive metabolic effects are observed before (or independently of) weight loss. This may be a result of the surgery itself, or a consequence of the marked caloric restriction that follows. The clinical use of bariatric surgery provides an excellent opportunity to use it as a model to understand the mechanisms of the adverse physiological effects of obesity. The use of bariatric surgery as an experimental tool will provide important insights into gut-brain interactions, linking priorities in mechanistic and neuroendocrine research. Suggested developments include:
Global health
Obesity is a global problem, including low-income countries and sub-Saharan Africa, but its causes (aside from at the most fundamental level) and consequences vary across countries and regions. There are special challenges driven by the burden of disease in low-income countries and metabolic diseases represent one category of emerging non-communicable diseases.
Method development (including dietary behaviour)
In many areas, obesity research is limited by a need for improved methodology. In particular, accurate, informative but scalable measurement techniques applicable to large studies are required. For example, the assessment of energy expenditure by doubly-labelled water is accurate but too expensive and time-consuming to be applied to large cohorts. Developments in the following areas would be especially useful: