Before you head out to your favourite restaurant or order takeaway from your couch tonight, you may want to consider cooking at home instead.

Most people understand that eating out can mean consuming higher levels of sugar and fat but a new study shows they're also absorbing more phthalates.

These synthetic chemicals are endocrine disrupters that may disrupt hormones and cause fertility problems. They have also been linked to birth defects in young boys, behavioural problems and obesity.

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Phthalates can be found in products like perfume, hair spray and shampoo.

But it's their presence in the plastics used in food processing and packaging that is thought to be contributing to their high levels among people who eat out.

According to the study published last week in the Environment International journal, among the 10,000 people surveyed, those who had eaten in restaurants, cafeterias and fast-food outlets the day before being tested, had 35 per cent higher levels of phthalates in their urine compared to people who ate food bought from a supermarket.

"The main idea is that food that is made in restaurants and cafeterias may be coming into contact with materials containing phthalates in part because some portion of the food is made in decentralised locations," a leading author of the study, Assistant Professor Ami Zota of George Washington University, told CNN.

"Most of the phthalates that are of most concern from a health perspective are plasticisers; they're added to make plastics soft," she added. "They're added to food packaging, they can be in food handling gloves, and they can be found in food tubing."

Teenagers seemed to be most at risk, with those eating out having 55 per cent higher levels of phthalate than those who didn't.

But Professor Zota said the phthalates only remain in the body for about a day so switching to home-cooked meals could have almost immediate health benefits.