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The obesity epidemic: What do chemicals have to do with it?

BPA, used in metal can linings, can have obesogenic effects—especially on developing children.

Used under creative commons license from beana_cheese

We are all hearing a lot about obesity these days and more people are obese than ever; one-third of American children and two-thirds of adults are overweight or obese. The American Medical Association has declared that obesity is a disease.

While some disagree with the designation of obesity as a disease, there is strong evidence that obesity is linked with diseases—specifically Type II diabetes and heart disease. There is also general agreement that obesity is a major public health problem. Preventing obesity would contribute to a healthier, happier population and save an estimated $190 billion per year in direct health care costs.

But how do we prevent obesity? We all know that we should eat healthier and exercise more to maintain a healthy weight, but few people are aware that avoiding exposure to certain chemicals could reduce their risk of obesity, especially during prenatal life and in childhood. An emerging body of science links chemicals that disrupt hormones to increased risk for obesity.

Fetuses and children are the most vulnerable to adverse health effects from hormone-disrupting chemicals. Like hormones themselves, these chemicals exert health impacts even at minute levels of exposure and exposures in the womb can have lifelong impacts.

As detailed in a new IATP fact sheet titled Chemicals and Obesity, an array of chemical obesogens may be contributing to the obesity epidemic. Obesogens are chemical agents that promote fat accumulation and alter feeding behaviors. They activate cell receptors to predispose them to fat accumulation. Obesogenic chemicals can affect the size and number of fat cells or the hormones that regulate appetite and metabolism. They can also cause changes in gene expression, or epigenetic changes, which can have intergenerational impacts.

It is now evident that a variety of environmental chemicals can act on cellular pathways to promote fat accumulation and obesity. We are all exposed to these chemicals every day through foods and food packaging and from an array of consumer products and building materials. Chemicals for which there is evidence of obesogenic activity include:

  • Bisphenol A, a chemical used in food packaging and plastic.
  • Phthalates, chemicals found in plastics and fragranced personal care products.
  • Brominated flame retardants used in electronics and foam products.
  • Perfluroalkyls, “Teflon chemicals” used in food packaging and nonstick cookware.


Evidence of obesity risk from chemical exposure is growing every day. A recent study found that girls aged between 9 and 12 with higher levels of BPA in their urine had a twofold increased risk for obesity.

In light of a growing obesity epidemic in the U.S., a comprehensive public health response is needed. In addition to initiatives to encourage healthy eating and exercise, we also need actions to prevent exposures to obesogenic chemicals, including:

  1. Better regulation of toxic chemicals through reform of the Toxic Substances Control Act (TSCA). TSCA should be strengthened to require the phase out persistent, toxic bio-accumulative chemicals that build up in the food system and in the human body and to require basic safety testing on all new chemicals introduced into commerce.
  2. Better state regulation of chemicals in children’s products through the Toxic Free Kids Act. Three of the above listed chemicals are on the Minnesota Priority Chemicals List.
  3. Voluntary efforts by downstream businesses and retailers to require the phase out the worst chemicals, including those linked with obesity.

Read IATP’s latest fact sheet, Chemicals and Obesity, for more.