A leading US politician has questioned whether food and drinks companies will voluntarily combat the issue of rising child obesity in the country.

Edward J. Markey slammed five of the country's top food and beverage companies for not committing to the same standards on children's food outlined last month by Kellogg.

Kellogg, the world's largest cereal maker, decided to improve the nutritional content of products it sells to children and tighten its marketing of such products.

Markey said he asked General Mills, Kraft Foods, McDonald's, PepsiCo and The Coca-Cola Co. to voluntarily implement the "same restrictions on marketing to children recently announced by Kellogg".

"These top food and beverage companies have an opportunity to play an important role in helping our children make healthier choices," said Markey. "I'd like these companies to supersize their commitment to public health and take steps to refrain from targeting young kids with certain food marketing. If Snap, Crackle, and Pop can do it, why can't Ronald McDonald?

Markey added: "The vague and incomplete responses from these companies, at a time when our country is facing a serious childhood obesity crisis, again raise the question of whether voluntary industry action will be sufficient to combat this important public health issue."

According to Markey, only Coca-Cola Co. gave him details of marketing restrictions with "any real impact".

Officials at the five companies could not be reached for immediate comment.