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James Roemmich, PhD.


Research Teams


Healthy Body Weight Research Unit
(James Roemmich, PhD. - Acting Research Leader)


Dietary Prevention of Obesity-Related Disease Research Unit
(Jay Cao, PhD, Research Leader)



U.S. Dietary Guidelines Adherence and Healthy Body Weight

Research addresses the effectiveness of dietary and physical activity practices based upon the USDA Dietary Guidelines for Americans in preventing unhealthy weight gain and minimizing risk factors for obesity-related chronic disease. The project includes studies to increase the motivating value of physical activity, fruits and vegetables such that adherence to the U.S. Dietary Guidelines might be improved. Contemporary behavioral change models and state-of the-art instrumentation are applied to the conduct of both controlled feeding and community-based studies.

Shanon Casperson, PhD - Research Biologist

Julie Hess, PhD - Research Nutritionist

James Roemmich, PhD - Supervisory Research Physiologist



Biology of Obesity Prevention

Research addresses the underlying physiological functions affected by diet and physical activity in the maintenance of healthy body weight. This includes the trans-generational programming of energy metabolism. The tools of genomics and metabolomics are utilized to elucidate the factors affecting individuals' responses to dietary and physical activity interventions, including the propensity of some individuals to gain weight. It involves studies with animal models as well as human volunteers.



Food Factors to Prevent Obesity and Related Diseases

Research addresses the appropriate levels and composition of dietary fats needed to maintain health and prevent diseases including cardiovascular disease and bone loss. Studies include determining the effects of different fats and genetics on energy metabolism in people, determining the role of omega-3 fatty acids in maintaining bone health, determining the effects of obesity on omega-3 metabolism, and determining the benefit of eating high omega-3 fish on cardiovascular disease markers in at-risk people. This work utilizes a unique combination of clinical and mechanistic studies coupled with state-of-the art instrumentation for assessment of energy metabolism, lipidomics, and genomics.


Modification of Diurnal Patterns to Promote Health in Models for Human Metabolic Dysfunction

This project takes innovative approaches to addressing how timing of meals and physical activity can correct the disruption of biological rhythms in peripheral organs caused by environmental cues that lead to metabolic dysfunction and disorders, including obesity. Results from this research will provide information of how dietary fatty acids and exercise minimize metabolic dysfunction and prevent associated disorders, a greater understanding of food timing and dietary fiber in regulating bile acid pathways and informing guidance for reducing colonic inflammation, and a greater understanding of timing of exercise training in improving bone health, particularly to people with bone loss associated with advancing age. 

Jay Cao - Research Nutritionist

Lin Yan- Research Nutritionist and Lead Scientist

Huawei Zeng- Research Molecular Biologist



USDA ARS Collaboration


Forrest Nielsen- Cooperating Scientist