The documentary "Super Size Me," a critical look at the health impact of a fast-food-only diet, has been downsized at MTV: The cable network has refused to show ads for the film, its distributors said Wednesday.

Roadside Attractions and Samuel Goldwyn Films said in a statement that MTV has told them the ads are "disparaging to fast-food restaurants."

The distributors said MTV sister network VH1 was planning to use clips from the movie in a program called "Best Week Ever," but the clips were pulled before the show aired.

An MTV spokesperson was unavailable for comment. MTV and VH1 are owned by media giant Viacom, which depends on advertising for a major portion of its revenues.

For "Super Size Me," director Morgan Spurlock had nothing but food and drink from McDonald's restaurants for 30 days, and if asked whether he wanted the larger, "supersize" meal, he always said yes. He gained weight and his health declined. Documenting the impact are not only the cameras but also his doctors. Spurlock mixes in facts and figures about food and dieting as he travels the United States talking to health and food experts in 20 cities.

In March, McDonald's said it would eliminate its supersize menu options by year end; a company spokeswoman said the decision was unrelated to the movie.

The announcement came two months after "Super Size Me" earned Spurlock the Grand Jury Prize for best documentary director at this year's Sundance Film Festival. The film began playing in theaters about two weeks ago and rose to No. 10 on domestic box-office charts this past week. It has grossed $2.9 million in ticket sales -- a hit for a documentary -- and last weekend scored a per-screen average of $6,759, just behind No. 2 film "Troy" with $7,014.

The film expands to 165 screens from 148 for the Memorial Day weekend, which the MTV ads had been timed to promote, a spokesman for the distributors said.

As not seen on MTV: Morgan Spurlock in the documentary "Super Size Me."