Understanding the connection between PFAS exposure, weight management, and the choices that support health and wellness
You may have seen headlines or social media conversations suggesting that PFAS, also known as forever chemicals, could contribute to weight gain and may even play a bigger role than nutrition choices. As a health coach and podcast host in this space, I felt it was important for us to look closer at the research and understand what we know.
PFAS stands for per- and polyfluoroalkyl substances, which fall into the category of what I call new to nature molecules. They are human-made chemicals used in production and industrial processes. More than 14,000 individual chemicals are included in this category. They are commonly found in products like waterproof jackets and shoes, stain-resistant fabrics, furniture, rugs, food packaging, reusable plastics, and personal care products like dental floss and shampoo. They are added to products to help resist heat, water, grease, and oil, similar to the coating used in a non-stick pan.
PFAS are often called “forever chemicals” because they do not break down easily in the environment or in our bodies. This means they can accumulate in our bodies, in animals, and in places like air, water, and soil. In modern life, we are surrounded by these chemicals, and without some awareness, it can be easy to increase our exposure. Research suggests that PFAS can pass through breast milk, umbilical cord blood, and the bloodstream, potentially building up in the body of a fetus or child before birth. PFAS exposure has been associated with several health concerns, including higher cholesterol, lower birth weights, reduced immune response to vaccines, kidney and testicular cancer, high blood pressure during pregnancy, and changes in liver function.
When it comes to my area of focus, I’m especially interested in the conversation around PFAS and weight gain. This discussion comes from a 2023 study that looked at whether these chemicals may influence weight regain after initial weight loss. Researchers followed 381 Europeans who lost at least 8% of their original weight over two months. Afterward, researchers tested participants’ blood for PFAS levels. The participants continued following their assigned nutrition plans for at least 26 weeks after the initial weight loss period. At the end of that time, the people who regained the most weight also had the highest levels of PFAS in their blood.
The researchers reported that participants in the highest third of PFAS exposure regained an average of about 10 pounds more than those in the lowest third of exposure. They suggested that higher PFAS exposure may have had a stronger relationship with weight regain than the nutrition plan participants followed. Essentially, the researchers suggested this could be one reason some people may respond differently to the same approach to weight loss, possibly because PFAS may influence hormones.
Since my work focuses on weight management and nutrition and lifestyle habits, I found this claim interesting and wanted to look closer. When reviewing the study, I noticed a few areas that made me curious. It was not clear whether researchers measured PFAS exposure only through blood levels or if they used additional ways to measure the amount of PFAS in participants’ bodies. I was also interested in what nutrition plans the participants followed.
The study explained that there were five “ad libitum” diets, also known as ad-lib diets. This approach allows food to remain available without strict limitations. For this study, that means there was not a specific structure for how participants followed these five categories. The five diets were (1) a Low Protein, Low GI (Glycemic Impact) diet, (2) a Low Protein, High GI diet, (3) a High Protein, Low GI diet, (4) a High Protein, High GI diet, and (5) a Healthy “Controlled” Diet. Adding another layer, we know that two people can follow the same nutrition plan in very different ways.
This brings up several questions for me. To start, the lack of structure around how participants followed their nutrition plans could be one factor connected to why some people regained weight. Regular listeners of my podcast and readers of mine on Medium know that I support low glycemic nutrition with an emphasis on protein, fiber, and quality fats. A high glycemic approach may not support weight management in the same way, regardless of someone’s PFAS exposure. We also do not know whether the study’s prescribed nutrition plans followed the common advice of “eat less, move more.” As you know from following my work, this approach can sometimes create short-term changes followed by weight regain. Instead, I believe focusing on consistent nutrition habits matters, with changes in body composition becoming a side effect rather than the only focus.
I am by no means dismissing PFAS or the conversation around forever chemicals. I simply think it’s important to look beyond attention-grabbing headlines and think critically about the information we see in the news and on social media. The goal is not to chase every new health headline and completely change your approach each time. Long-term health and wellness often come from consistent, informed choices and small steps that fit your life.
At the same time, I agree that environmental exposure to chemicals is another piece of the relationship between our bodies and the modern world we live in. Understanding factors like PFAS exposure, nutrition, movement, and lifestyle habits can help us make more informed choices when it comes to our health.