WASHINGTON, DC: Expenditure on the marketing of e-cigarettes has increased significantly, prompting calls for tighter restrictions to prevent the sector advertising to youth.

According to an analysis of industry data by Truth Initiative, a public health organisation dedicated to the rejection of tobacco, e-cigarette advertising expenditures rose by 52% between 2013 and 2014 to reach $115.3m, with most of that spending going on magazines and cable TV.

It further reported that 82% of 12-17 year-olds and 88% of 18-21 year-olds had seen an e-cigarette ad in 2015.

Traditional cigarette advertising has not been permitted on US television for more than 40 years and Truth Initiative suggested that e-cigarette brands were purposefully targeting a young audience by running ads on networks such as Comedy Central, AMC, ESPN, VH1 and Spike.

The various flavours available, including gummy bear and cotton candy, are also designed for a younger age group.

Earlier this year, data published by the Centers for Disease Control and Prevention and the US Food and Drug Administration's Center for Tobacco Products indicated that e-cigarette use among middle and high school students had tripled between 2013 to 2014, from 4.5% to 13.4%.

"Advertising, particularly television, is extremely expensive and no advertiser would waste money against a target that is outside their intended audience," noted Robin Koval, CEO and President of Truth Initiative.

"These new data provide further evidence that the Food and Drug Administration must restrict e-cigarette marketing to youth."

The American Academy of Pediatrics has also called on the Food and Drug Administration to expand its jurisdiction to include e-cigarettes, liquid nicotine and all other tobacco products and for Congress to immediately raise the purchase age for such products to 21.

Cynthia Cabrera, president of the Smoke Free Alternatives Trade Association, which represents the e-cigarette industry, has argued that the product can save lives by helping smokers switch away from traditional cigarettes.

Data sourced from Truth Initiative, CDC, US News& World Report; additional content by Warc staff