About 40% 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 exposure to certain chemicals, sometimes called “obesogens,” may alter metabolism and predispose some people to weight gain. Environmental health scientists study how environmental exposures — especially those that occur during critical windows of development — influence weight gain, metabolism, obesity, diabetes, and related conditions.
What NIEHS is 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 (PCBs), dioxins, arsenic, pesticides, phthalates, and perfluorooctanoic acid, among others. Researchers examine exposures to individual contaminants and chemical mixtures.
NIEHS-funded researchers are also identifying new roles for chemicals as they tease apart the underlying causes of obesity. 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.
NIEHS-funded researchers who focus on developmental origins of obesity and metabolic dysfunction are examining the effects of preconception and prenatal exposures. Adult exposures, interactions between developmental and adult exposures, and transmission of effects across generations are important research areas. Researchers are also examining susceptibility to weight gain under various lifestyle conditions because, in some cases, the chemical effects do not manifest until after a person engages in certain lifestyle choices, such as eating a high-fat diet.
This research will help achieve a better understanding of the role of environmental factors in obesity and diabetes, which is necessary for developing prevention strategies.