Eleni Chechopolous told her 11,000 followers that their "battle with the scale" could be down to their choice of haircare.
Alongside an image of her holding a bottle of Pantene, Eleni wrote: "Is your shampoo making you gain weight?
"First its calories, then it's hormones, then it's gut health... now it's my shampoo!"
"Even though you eat healthy and exercise every day, you might still battle the scale because of your SHAMPOO. "
Eleni referenced studies on mice to support her claims, but they were dismissed by health and fitness expert, Belinda MacDougall.
Speaking to news.au.com, Belinda said: "To say shampoo is the reason we are overweight is ridiculous and while chemicals in all beauty products can be bad for our health, weight gain is far more related to what we eat."
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