Teenagers who drink sports or energy drinks every week are much more likely to smoke, drink higher amounts of other sugary drinks and spend more time watching various screens.

Sports and energy drinks are high in sugar and can be high in caffeine. They are a popular choice for teenagers, so US scientists set out to assess the health behaviours of young people who consume these drinks.

They looked at almost 2,800 teenagers during the 2009-2010 school year. The average age of participants was 14.

The scientists said that while the consumption of sports drinks was linked to higher levels of sports participation and physical activity, the consumption of sports and energy drinks overall appeared to be associated with a ‘clustering of unhealthy behaviours' among some teenagers.

For example, among boys, drinking sports drinks every week ‘was significantly associated with higher TV viewing'.

"Boys who regularly consumed sports drinks spent about one additional hour per week watching TV compared with boys who consumed sports drinks less than once per week," the scientists said.

Meanwhile, boys who consumed energy drinks every week ‘spent approximately four additional hours per week playing video games compared to those who consumed energy drinks less than once per week'.

Young people who consumed these drinks were also much more likely to smoke and consume other sugar-sweetened beverages, such as fizzy drinks.

Experts believe that teenagers should only consume sports drinks after vigorous and prolonged exercise, and energy drinks should not be consumed at all by young people as they may over-stimulate the nervous system.

The scientists from the University of Minnesota believe that interventions are needed to target these unhealthy behaviours in teenagers and to highlight the importance of consuming healthy drinks, such as water.

Details of these findings are published in the Journal of Nutrition Education and Behavior.