Obesogens Are Environmental Pollutants That May Alter the Body’s Metabolism And Predispose Some Individuals To Weight Gain.

Obesity rates in America have risen dramatically in the past 40 to 50 years. Today, over 35% of adults and 17% of children age 2 to 19 in the United States are obese with a BMI (body mass index) between 25 and 30. But, obesity isn’t just a problem plaguing Americans as obesity rates have also risen worldwide. Regardless of where they live, even those at the lower end of the BMI are gaining weight, suggesting that there may be more to weight gain than a sedentary lifestyle and lack of exercise. So, what gives?

While diet and exercise play a vital role in the current obesity epidemic, extensive research suggests environmental pollutants play a significant role as well. Called “obesogens,” these environmental pollutants may alter the body’s metabolism, thereby influencing how our body stores fat. This predisposes some individuals to weight gain, regardless of how dedicated they are to a healthy diet and exercise.

What are Obesogens?
Obesogens are known as “endocrine disruptors” because they interfere with the endocrine system, which coordinates the functions of various organs and systems in our body. Endocrine disruptors interfere with natural hormone systems, and the health effects can be felt long after the exposure has stopped. These obesogen chemicals are found in plastic bottles and containers, liners of metal food cans, detergents, personal care products, flame retardants, food, toys, cosmetics and pesticides, according to the National Institute of Environmental Health Sciences.

How do obesogens contribute to weight gain?
Convincing evidence has determined that obesogens alter how fat cells in our body behaves; they can increase the size of fat cells, or the quantity of fat cells, or influence the hormonal actions associated with metabolism. Remember, fat has an important purpose related to survival, which is to store energy that can be used later as needed. Fat is also an important part of the endocrine system, as it stores and releases hormones.

Although people of all ages are at risk to chemical exposure, children and pregnant women are particularly vulnerable to obesogens. When a fetus is exposed to the chemicals, the consequences may extend to future generations by altering DNA and gene expression. The impact on the fetus tends to last throughout childhood and into adulthood, and it can be very difficult to reverse the effects. This may explain why it’s so challenging for some kids and adults to lose weight, no matter how hard they try.

An article published in Environmental Health Perspectives gives an excellent overview of how obesogens are contributing to the expanding American waistline. It starts by saying “Many in the medical and exercise physiology communities remain wedded to poor diet and lack of exercise as the sole causes of obesity. However, researchers are gathering convincing evidence of chemical “obesogens”—dietary, pharmaceutical, and industrial compounds that may alter metabolic processes and predispose some people to gain weight.”

I have discussed many specific obesogen chemicals in previous blogs. They include industrial chemicals such as BPA and phthalates (related to plastics), PFOA (Teflon), and PCBs (electronics) and PBDEs (fire retardants). Pesticides, lead, and benzopyrenes are other environmental toxins. Pharmaceuticals such as estradiol and diethylstilbestrol (DES, a drug given to pregnant women to prevent miscarriage), and even foods such as fructose and MSG (a flavoring additive) may act as obesogens.

Is weight loss being made more difficult because of our environment?
Extensive research suggests this to be true. In part two of this blog, I will review specific obesogenic actions that have been identified and offer suggestions on how to minimize exposure and counteract their affects.

Environ Health Perspect. 2012 Feb;120(2):a62-8. doi: 10.1289/ehp.120-a62.