Gains made from weight loss diets and regular exercise can be compromised by chemicals in the utensils and packaging used to prepare and store otherwise healthy food. This is the conclusion of a Harvard-led study that found a correlation between obesogens and weight increase among dieters.

The technical term for obesogens is “perfluoroalkyl substances” (PFAS). They are a class of chemicals that have been used in food wrappers, pots, pans, and other consumer and industrial products for the last 60 years. Called “obesogens” because of their disruptive effect on the body’s normal way of regulating weight, PFASs can lower the resting metabolic rate (RMR) of people, causing their bodies to burn fewer  calories while they are at rest. People with low RMR will gain weight more easily unless they adjust their food intake to account for the imbalance in their metabolism.

For their study of the effects of PFASs on human metabolism, researchers of Harvard T.H. Chan School of Public Health cooperated with their counterparts from Louisiana State University and Tulane University.

“Obesogens have been linked with excess weight gain and obesity in animal models, but human data has been sparse,” said Qi Sun. The senior author of the study, she is a assistant professor in the Department of Nutrition at Harvard Chan School.

“Now, for the first time, our findings have revealed a novel pathway through which PFASs might interfere with human body weight regulation and thus contribute to the obesity epidemic,” she reported. (Related: Boost your metabolism AND the microbiota in your colon with a small amount of prebiotics.)

Study details

Data for the study was derived from the Prevention of Obesity Using Novel Dietary Strategies (POUNDS LOST,) a two-year-long clinical trial that tested several diets for weight loss. Researchers looked at the PFAS blood concentration level of participants at the start of the trial and the weight losses and gains of the participants.

The weight of POUNDS LOST participants dropped by an average of 14.1 pounds (6.4 kg) during the first six-months-long quarter of the trial. They regained an average of 5.95 pounds (2.7 kg) over the course of the following 18 months.

According to the study, the participants who regained the most pounds also showed the highest amount of obesogens in their bloodstreams. The correlation was considered to be stronger in women than in men. Women with the greatest concentration of perfluoroalkyl substances in their blood regained an average of 3.7 to 4.9 pounds more than women with the lowest amounts of PFAS.

The researchers further confirmed that participants with high levels of PFASs also had low resting metabolic rates, which could account for the larger amounts of weight they regained during the latter part of the diets.

Yet another mark against PFAS

“We typically think about PFASs in terms of rare health problems like cancer, but it appears they are also playing a role in obesity, a major health problem facing millions around the globe,” said  Philippe Grandjean, an adjunct professor of environmental health and co-author of the study alongside Sun.

There are numerous cases of PFAS contamination of potable ground water that have been traced to nearby factories, military bases, and wastewater treatment plants. The Harvard-led study adds obesity to the long list of associated ill effects such as cancer, disruption of hormones, dysfunctional immune systems, and dangerous levels of cholesterol.

“The findings suggest that avoiding or reducing PFAS exposure may help people maintain a stable body weight after they successfully lose some weight, especially for women,” Grandjean recommended.

Sun, Grandjean, and their colleagues published their findings on obesogens in PLOS Medicine.

Sources include:

Science.News.com

Journals.PLOS.org

ScienceDaily.com