Brenda Davy: Building Evidence for Effective Weight Managment Strategies
You may be surprised to learn that until recently, despite widespread beliefs that drinking water is part of an effective weight loss strategy, there has been little empirical evidence to support these claims. Over the past decade, however, Brenda Davy, a professor in the Department of Human Nutrition, Foods and Exercise in the College of Agriculture and Life Sciences at Virginia Tech, has been conducting rigorous research on water consumption and other weight management strategies.
“I am interested in how health behaviors, such as diet and physical activity, impact weight management and chronic disease risk for cardiovascular disease or Type 2 diabetes,” said Davy. Her studies on water consumption are one strand of this research.
Davy has received funding from the Institute for Society, Culture and Environment (ISCE), both as an ISCE Scholar and through unsolicited proposals, to support pilot work related to her water consumption studies as well as some of her other research. These pilot studies have led to numerous National Institutes of Health (NIH) grant applications that build upon her research program’s history of securing funding, including three NIH awards totaling close to $5 million that Davy secured as the lead investigator.
Davy conducted one of the first randomized controlled trials evaluating pre-meal water consumption on weight loss. She found that consuming approximately two cups of water three times per day before a meal was an effective strategy for weight loss and maintenance for middle-aged and older adults taking part in a behavioral weight loss program.
“Our study was one of the first to intentionally manipulate water consumption and show its impact among participants on a hypocaloric diet,” Davy said.
She is actively pursuing additional funding from NIH to extend these results. The initial study included 48 participants, the majority of whom were Caucasian and female. If funded for another trial, Davy plans to expand the scope of the study to include a larger number and more diverse participants and to evaluate mechanisms by which water consumption may facilitate weight control.
“Most of the work that we are doing really falls into the efficacy/effectiveness phase of the translational research spectrum. My work on water and weight management has potential clinical impact. Continued work in this area could result in new guidelines for water consumption for middle aged and older adults seeking weight management interventions,” said Davy.
She has also published a systematic review article with lead author and colleague Assistant Professor Ben Katz, also an ISCE awardee from the department of Human Development and Family Science, that examined water status and the impact on cognitive function. “I hope to incorporate some of these elements into my future research on water consumption,” Davy said.
Another area of research Davy has focused on is resistance training in older adults. She and colleagues demonstrated that resistance training two times per week alone, with no other lifestyle change, was an effective, maintainable strategy for reducing pre-diabetes prevalence and increasing muscular strength in older adults with overweight or obesity who are sedentary.
Davy is also interested in dietary intake assessment. “I have been studying how dietary biomarkers, which are objective indicators of dietary intake, such as can be found in urine or blood, can be used to support self-reported dietary information,” explained Davy.
In the past, most dietary studies relied on self-reported dietary data from participants, which at times, could be very subjective. Biomarker data provide a more objective means to validate what participants report and help researchers tease out mechanisms related to diet and its impact on overall health.
This type of work has led to her most recent interest in studying ultra-processed foods. “More than half of the calories consumed in the U.S. are from ultra-processed foods. There are observational studies linking consumption of these types of foods to adverse outcomes such as weight gain, obesity, and type 2 diabetes. However, we want to conduct experimental research that looks at causal links between ultra-processed foods and health outcomes,” said Davy.
Davy relies heavily on students to help conduct her research and she considers graduate student training as one of her top priorities. She directs the Laboratory for Eating Behaviors and Weight Management which includes a metabolic kitchen and dining laboratory. Davy is also fortunate to be able to integrate her teaching and research interests; she regularly teaches a graduate course focused on research methods related to diet and physical activity.