The drivers of obesity are complex and individual behavioral factors are not independent from genes, physiology, the brain, and the influence of the environment. For example, there is general agreement that a permissive food environment, low levels of physical activity and sedentary lifestyle contribute to obesity. However, environmental factors, alone, are unlikely to fully explain differential risk for obesity development or response to treatment. Within similar environments there is considerable individual variability in weight or weight gain trajectory. Further, despite the evidence that behavioral weight loss can be efficacious and lead to meaningful health outcomes, there is wide variability in response to prevention and treatment interventions, and varying degrees of maintenance of weight loss following an intervention. Underlying genetic, epigenetic, and metabolic factors interacting with the environment likely contribute to this individual variability. To better understand this complexity, there is a need to improve the depth of our understanding about the contributing factors at the various levels of analysis; including individual behaviors and psychological factors that contribute to endophenotypes.
For the purposes of funding opportunity, a behavioral or psychological phenotype is defined as a pattern of behavior or psychological characteristics that are measurable/quantifiable and distinct (explains individual variation). An endophenotype is an intermediate phenotype that is the result of the combination of what is inherited and the environment. The goal of this initiative is to identify the behavioral and/or psychological expression (phenotype) of this interaction that meaningfully explains individual variability in weight gain trajectory, response to prevention or treatment, and treatment engagement and adherence. The identification of these phenotypes should improve treatment matching or identify novel targets for more efficacious individual and population level approaches for weight management.
Types of ancillary studies might include, but are not limited to:
- Addition of objective measurement of weight, BMI, and/or body composition to studies that are already obtaining detailed measurement of psychological characteristics hypothesized to be related to individual weight variability including obesity development and response to interventions.
- Addition of measures of psychological factors and/or an objective measurement of eating behavior in studies that are already objectively measuring weight, BMI and/or body composition.
Addition of measurement in a domain already covered in the parent (e.g.; a new body composition measure in a study that already includes measures of body composition), is not consistent with the intent of this funding announcement. The goal is to support the addition of new measurement in domains other than those covered in the parent grant as a means of elucidating the behavioral and psychological factors that may explain individual differences in weight status.
Studies can be ancillary to longitudinal observational research or intervention trials. Applicants can propose ancillary studies to ongoing R01 or equivalent studies as well as major ongoing clinical trials or longitudinal observational epidemiological studies. Studies can be ancillary to research funded at agencies other than the NIH but, regardless of the funder, applicants must clearly demonstrate approval and cooperation from the PD/PI or study team of the parent grant for the activities proposed in response to the funding opportunity announcement.
Regardless of the type of study design, there must be a plan to measure the variables of interest in the same cohort at a minimum of two well justified time points. Cross sectional and purely correlative research is not consistent with the goals of this initiative.
Studies with well-articulated mechanistic hypotheses are encouraged. We would also encourage research that examines how the behavioral or psychological factors measured interact with measures of brain processes, physiological variables thought to drive obesity, genetic, and environmental or social influences. Studies include collaborations between experts in psychological/behavioral measurement and metabolic phenotyping are encouraged.
Behavioral and/or psychological characteristics of interest include, but are not limited to:
- Objective observation of eating behavior such as quantity, selection/quality, and speed of intake.
- Underlying psychological processes of self-regulation thought to be related to obesity prevention or treatment response. Self-regulation is the process of managing emotional, motivational and cognitive resources to align mental states and behavior with energy intake goals. Additional measures proposed should already be well validated for the population and mode of assessment.
- Disinhibited eating such as loss of control, dietary restraint, and response to external or internal food cues;
- Learning/motivational processes such as reward sensitivity, model-free and model-based reward learning, and reward maximization and effort minimization;
- Cognitive processes such as simple and complex attention; executive function and working memory, including mental set-shifting, goal updating and monitoring, and cognitive control (response selection, inhibition, or selection); and
- Affective /emotional characteristics such as high/low valence and arousal or patterns of approach and avoidance.
Primary outcomes must include weight, BMI, body composition or objective measures of eating behavior. Self-reported measures of dietary intake will not be sufficient as a primary outcome. For the purposes of this FOA, a focus on energy intake must include objective measures of energy intake such as doubly labelled water, direct observation of energy intake, use of technology to record aspects of eating in real world settings such as use of photography or monitors that capture eating episodes, or other validated technologies from which calculation of energy intake reliably can be derived, such as doubly labeled water. Psychological or behavioral measures should have demonstrated validity and reliability. Where possible, use of existing and well validated measurement tools is encouraged (e.g.; HealthMeasures (http://www.healthmeasures.net/) such as PROMIS, NIH Toolbox, and Neuro-QoL or PhenX https://www.phenxtoolkit.org/ )).
Research is encouraged in populations across the life course and identifying behavioral or psychological phenotypes in high risk or underserved populations is also a priority.
Research submitted to this FOA should be in human subjects. Research in animals is not consistent with the aims of this FOA.
Deadline: letters of intent are due 30 days before the full proposal is submitted; October 28, 2016; February 28, 2017; June 28, 2017; February 28, 2018; June 28, 2018; February 28, 2019 (full proposals)
Filed Under: Funding Opportunities