Why you should avoid non-stick pots and pans if you want to lose weight

Henry Bodkin
Perfluoroalkyl substances, which are found in cooking pans, have been linked to obesity -

People trying to lose weight should avoid cooking with non-stick pots and pans, a new study suggests.

Fresh research into chemicals known as perfluoroalkyl substances (PFASs), which are also present in paper plates and grease-proof paper, found a link between levels in the blood and an inability to diet.

Previous research had already associated PFASs with cancer, hormone disruption and immune system dysfunction, however data showing the effects on human weight gain had been sparse.

Harvard University analysed 621 obese and overweight people over two years as they attempted to diet.

The team found that during the first six months of the trial, participants lost an average of 6.4 kg, but regained 2.7 kg over the course of the following 18 months.

Those who gained the most weight back also had the highest blood concentrations of PFASs, and the link was strongest among women.

On average, women who had the highest PFAS blood levels - in the top third - regained 1.7 to 2.2 kg more body weight than women in the lowest third.

Mapped England’s obesity hotspots

PFASs have been used for more than 60 years in products ranging from food wrappers to clothing to pots and pans.

The chemicals can accumulate in drinking water and food chains and remain in the human body for lengthy periods.

The Harvard team suggested PFASs may be slowing down metabolism, which makes it harder to lose weight.

"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 study co-author Professor Philippe Grandjean.

"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."

The study was published in the online journal PLOS Medicine.