Maintaining weight loss is extraordinarily difficult for most people for myriad reasons, some understood and others less so.
In February, PLOS Medicine published results of the first randomized controlled human study looking for connections between weight loss and exposure to synthetic chemicals called perfluoroalkyl substances (PFAS). The researchers found that higher blood levels of PFAS don’t affect weight loss but are associated with greater weight regain, especially in women.
PFAS are present in many nonstick and waterproof consumer products, as well as in some food packaging and public water supplies. The PFAS likely increase weight regain by disrupting endocrine function, causing a greater decline in resting metabolic rate with weight loss and a lower increase in resting metabolic rate during weight regain.
A 2007 study in the journal Environmental Health Perspectives found that more than 98% of participants had detectable PFAS levels in their blood. In U.S. consumer products, the chemical is used less frequently than it was in the past, but usage is highly prevalent throughout the world. PFAS are very stable and have a long half-life, making elimination a challenge.