About 42% of adults in the U.S. are obese, according to the Centers for Disease Control and Prevention. Obesity increases the likelihood of conditions such as heart disease, stroke, type 2 diabetes, and certain types of cancer.
Although nutrition, activity level, and genetics all play important roles in the development of obesity, increasing evidence suggests that exposure to certain chemicals, sometimes called “obesogens,” may alter metabolism and predispose some people to weight gain and metabolic problems. Environmental health scientists study how environmental exposures — especially those that occur during critical windows of development — influence weight gain, metabolism, obesity, diabetes, and related metabolic conditions.
What Is NIEHS Doing?
NIEHS-funded researchers use animal models and epidemiological studies to better understand how exposures to air pollution and other environmental contaminants might increase risk for obesity, diabetes, and metabolic dysfunction.
Chemicals under study include bisphenol A, polychlorinated biphenyls, dioxins, arsenic, pesticides, phthalates, and perfluorooctanoic acid, among others. Researchers examine exposures to individual contaminants and chemical mixtures.
Researchers are also uncovering new roles that chemicals may play in the development of metabolic conditions. They work to understand how chemical exposures affect diabetes and liver lipid disorders, and how they may disrupt metabolism in a way that leads to metabolic syndrome. Metabolic syndrome is a group of factors, such as cholesterol and blood glucose, that increase the chance of heart disease, stroke, and type 2 diabetes.
Some NIEHS-funded researchers focus on exposures that occur before and during pregnancy to better understand developmental origins of obesity and metabolic dysfunction. Adult exposures, interactions between developmental and adult exposures, and intergenerational transmission of effects are important research areas as well.
Researchers are also examining susceptibility to weight gain under various lifestyle conditions. In some cases, chemical effects do not appear until after a person engages in certain lifestyle choices, such as eating a high-fat diet.
Collectively, this work will improve our understanding of how environmental factors affect obesity, diabetes, and metabolic health, and will inform prevention strategies.