LONDON--Coca-Cola is understood to have called in agency support to help promote the health and lifestyle benefits of its low-calorie drinks.

The drinks giant has appointed a group of Interpublic Group (IPG) agencies, led by McCann Health, to the integrated brief. The selection follows a competitive review in late 2012 that included agencies from at least one other holding group.

According to sources familiar with the assignment, the brief focuses on Coca-Cola’s low-calorie drinks portfolio, including the iconic Diet Coke brand. Led from London, the assignment covers international markets.

It comes amid a high-profile attempt by the company to raise awareness of its low-calorie drinks, which now account for around a third of its sales. Last month, Coca-Cola released the two-minute ‘Coming Together’ ad, marking its first attempt to enter the mainstream debate around obesity and sugary beverages.

A key component of this strategy is the message that Coca-Cola’s low-calorie drinks encourage an active and healthy lifestyle. The company has faced considerable scrutiny of the ingredients in these drinks, notably artificial sweetener aspartame. Diet soda, meanwhile, has been linked to increased heart disease and stroke risks.

Coca-Cola has recently begun adopting an alternative sweetener - stevia - which is now used in its Glaceau Vitamin Water drinks in the UK, after being cleared by the EU in 2011.

It is understood that the IPG agency offering includes at least one public relations firm. Weber Shandwick is unable to work on Coca-Cola business because of its existing association with Pepsico, but there are not thought to be any significant conflicts for other IPG PR firms, such as GolinHarris or DeVries Slam. Coca-Cola is one of ad agency McCann Erickson’s key global clients.