Artificial sweeteners contain gender bending chemicals that make people fat, warns new research.
Known as 'obesogens' they interfere with how our hormones work - fuelling the obesity crisis.
They reprogramme the body making it pile on the pounds through boosting the number and size of fat cells or increasing appetite.
They can also make it more difficult to lose fat by changing our ability to burn calories, say scientists.
Dr Ana Sousa, of the University of Aveiro in Portugal, said: "Obesogens can be found almost everywhere, and our diet is a main source of exposure, as some pesticides and artificial sweeteners are obesogens.
"Equally, they are present in plastics and home products, so completely reducing exposure is extremely difficult - but to significantly reduce it is not only feasible, but also very simple."
Many dieters switch to the sugar substitutes to avoid the calories while still getting their sweet-tooth rush.
The sweeteners, such as saccharin and aspartame, are used in thousands of diet products including drinks, desserts, ready meals, cakes, chewing gum and even toothpaste.
But evidence is growing linking them to weight gain and increased risk of diabetes, high blood pressure and heart disease.
Dr Sousa said minimising exposure to obesogens will combat obesity. Britain is the most obese nation in Western Europe, with almost two in three of UK adults overweight.
Her review of epidemiological and animal studies identified diet, house dust, cleaning chemicals, kitchenware and cosmetics as the main sources of exposure.
Obesogens like tributyltin and cadmium can be found in food products - in some cases at high concentrations.
Tributyltin was banned from use in anti fouling paint on ships' hulls a decade ago. It was shown to be causing crustaceans to change sex. Cadmium is an environmental metal that has been linked to cancer
Obesity increasingly affects millions of people worldwide with cases rising sharply in young children and babies - a trend which is not explained by evolving diets and lifestyles alone.
The condition contributes to an estimated 2.8 million deaths per year worldwide and leads to many other health complications, which are a large financial burden on healthcare systems.
Previous studies have identified obesogens in everyday products ranging from pesticides, plastics, flame retardants and repellent coatings on kitchen utensils to clothes and artificial sweeteners.
Based on the findings presented at the European Society of Endocrinology annual meeting in Barcelona, the researchers suggest specific recommendations including:
* Choosing fresh food over processed products with long lists of ingredients on the label - the longer the list, the more likely the product is to contain obesogens.
* Buying fruit and vegetables produced without pesticides, such as certified organic or local pesticide-free products.
* Reducing the use of plastic, especially when heating or storing food. Instead, use glass or aluminium containers for your food and drinks.
* Removing shoes when entering the house to avoid bringing in contaminants in the sole of shoes.
* Vacuuming often, using high-efficiency particulate air (HEPA) filters and dust your house frequently using a damp cloth.
* Removing or minimising carpet at home or work, as they tend to accumulate more dust.
* Avoiding cleaning products when possible, or choose those that do not contain obesogens.
Dr Sousa said further studies are needed in order to provide unequivocal evidence of how obesogens contribute to the obesity epidemic.
She added: "These are baby steps to achieve an obesogen-free lifestyle but a really good start. Essentially, watch your diet and get rid of the dust at home.
"Adults ingest about 50mg of dust every day, and children twice as much, so keeping the house clean is a very effective measure.
"And use a humid cloth to dust your furniture, rather than a cleaning product that may contain more of these chemicals."
Further work in Dr Sousa's research group includes a case control study to evaluate obesogen levels in Portuguese obese patients.
Additionally, they intend to launch a new cohort study to monitor obesogen levels in urine and hair of pregnant women, and in their children, to further determine how obesogens affect their obesity risk.