Teenagers with irregular sleeping patterns consume more calories each day and are much more likely to snack at nighttime, the results of a new study indicate.

US researchers analysed the sleeping patterns of almost 350 teenagers, who slept, on average, for about seven hours per night.

The study found that if the amount of time the teenagers slept varied by an hour or more - whether this was an hour more or an hour less sleep - these young people consumed over 200 calories more per day, including around 6g more of total fat and 32g more of carbohydrates.

They were also 60% more likely to snack on a school night and 100% more likely to snack at night over the weekend.

"According to the data from our study, it's not how long you sleep that matters. It's about day-to-day variations in how long you sleep," said the researchers from the Penn State University College of Medicine.

They suggested that changing sleep patterns may result in a hormonal imbalance, which could cause the teenagers to eat more. They also suggested that if a teenager gets less sleep one night, they may be more sedentary the next day, becoming a ‘couch potato' and snacking more.

"It may be more important to have a regular sleep pattern than to sleep longer one day and shorter on another. These findings could help us better understand how obesity develops among young people," they added.

Details of these findings were presented at the American Heart Association EPI/Lifestyle 2015 meeting in Maryland.