NEW YORK (AP) --

The Federal Trade Commission on Wednesday said it issued warnings to two food and beverage industry groups, as well as a dozen online influencers, for failing to adequately disclose paid social media posts that promoted a sweetener and sugary products.

The letters point to Instagram and TikTok posts made by the influencers who were apparently hired by the American Beverage Association, a lobbying group whose members include Coca-Cola Co. and PepsiCo, and the Canadian Sugar Institute, which represents Canadian sugar manufacturers.

The warnings follow updated guidelines the agency published this summer requiring influencers to prominently disclose advertisements and paid social media posts that promote products for companies.

The FTC said it reviewed posts by health influencers -- including registered dieticians -- who endorse "sugar-containing products" and appear to be paid by the Canadian Sugar Institute.

Meanwhile, the agency warned the American Beverage Association about posts that tout the safety of aspartame, a sweetener found in diet soda and countless other foods. In July, the World Health Organization's cancer agency deemed the sweetener could be a possible cause of cancer, though other experts assembled by the health organization have said aspartame is safe to consume in small quantities.

The FTC said some of the posts it reviewed had no disclosures. Others had disclosures in the text description of the videos, but not in the videos themselves. Some of the dieticians identified "ameribev" as their partner, but the agency said that was inadequate since viewers may not understand the abbreviation for the American Beverage Association.

"It's irresponsible for any trade group to hire influencers to tout its members' products and fail to ensure that the influencers come clean about that relationship," Samuel Levine, director of the FTC's Bureau of Consumer Protection, said in a statement.

The agency wrote in the letters to the trade groups that the posts may violate federal law and could cost them up to $50,120 in penalties per violation. Neither the American Beverage Association nor the Canadian Sugar Institute immediately responded to requests for comment.