Using a smartphone at mealtimes can lead to an expanding waistline， say scientists.

Researchers have found that men and women consumed 15 percent more calories when looking at theirphones while eating. They also ate more fatty food.

The groundbreaking study suggests that staring at a phone screen may distract diners from how muchfood they are actually eating.

"It may prevent the correct understanding of the brain over the amount of food ingested，"saidresearchers who filmed 62 volunteers eating alone.

The men and women， aged 18 t0 28， were invited to help themselves to a choice of food - ranging fromhealthy options to soft drinks and chocolate - until they were satisfied. In three trials， the volunteers wererecorded eating with no distractions， using a smartphone or reading a magazine.

On average， the volunteers ate 535 calories without the distraction of a smartphone but 591 when usinga mobile.

Those in the sample who were classed as overweight ate 616 calories while using their phones. Whenin possession of their mobiles， the volunteers also consumed 10 percent more fatty food. They also ate morewhen reading a magazine.

"Smartphone use during a meal increased calorie and fat intake，"said Marcio Gilberto Zangeronimoa，a lead author of the study - carried out at the Federal University of Lavras in Brazil and University MedicalCenter Utrecht in the Netherlands.

He added， "Tablets and smartphones have become the main 'distracters'during meals， even early inchildhood， so it is important to pay attention to how this may impact food choices."

"A distracter prevents the brain correctly understanding the amount of food ingested."

The study is published in the journal Physiology And Behavior.