Qi Sun, M.D., Sc.D.
R01ES022981, R01ES021372, R01ES021477
A new study by NIEHS grantees suggested that exposure to perfluoroalkyl substances (PFASs) might make it harder to keep weight off after dieting. The researchers found that levels of PFASs in the blood were linked to greater weight gain in study participants who had recently shed pounds, especially women. People with higher blood levels of PFASs also had lower resting metabolic rates overall, meaning they burned fewer calories during normal daily activities.
The study authors used data from the two-year Preventing Overweight Using Novel Dietary Strategies Lost trial, a clinical trial in which overweight and obese individuals followed controlled weight reduction diets that restricted daily caloric intake. In the trial, weight loss generally occurred in the first 6 months, followed by 18 months of gradual weight regain.
As part of the study, five specific PFASs were measured in participants’ blood. Researchers observed that the higher the blood levels of PFASs, the more weight was gained back after the initial period of weight loss. Higher blood levels of these PFASs were also correlated with lower resting metabolic rates during the weight regain period.
Taking these two associations together, the researchers proposed that certain PFAS chemicals might contribute to weight gain by lowering the body’s resting metabolic rate, a novel pathway through which PFASs interfere with human body weight regulation.
Citation: Liu G, Dhana K, Furtado JD, Rood J, Zong G, Liang L, Qi L, Bray GA, DeJonge L, Coull B, Grandjean P, Sun Q. 2018. Perfluoroalkyl substances and changes in body weight and resting metabolic rate in response to weight-loss diets: A prospective study. PLoS Med 15(2):e1002502.