Pro athletes are always warned to be careful about supplements that may contain banned substances, but one sport is warning athletes to watch what they eat.

FOX's Chris Hoenig reports:

Steak and potatoes sounds like a good meal for a football player, but it could get some suspended. Athletes in several sports have tested positive for Clenbuterol after eating tainted beef from China and Mexico, where cows are illegally given the drug to try to make them meatier.

The Raiders and Texans are scheduled to play each other in November in Mexico City, prompting the league to warn players against eating large quantities of meat while visiting the country.

Texans offensive lineman Duane Brown tested positive for Clenbuterol last season after eating 10 hamburgers on vacation in Mexico. His 10-game suspension was overturned on appeal.

Chris Hoenig, FOX News.

Follow Chris Hoenig on Twitter: @Chris_Hoenig