The NFL’s drug-testing administrator sent a memo to the league’s players Tuesday warning them against eating too much meat produced in China and Mexico, according to ESPN. It turns out meat from those countries contains a muscle-building and weight-loss stimulant called elenbuterol, which could cause a positive performing-enhancing substance test.

"Players are warned to be aware of this issue when traveling to Mexico and China," the memo said. "Please take caution if you decide to consume meat, and understand that you do so at your own risk."

With a large headline reading "Warning: Contaminated Meat," the NFL reiterated its common refrain: "players are responsible for what is in their bodies."

Arizona Cardinals corner Patrick Peterson, who tweeted a photo of the memo, was clearly dismayed, as were other NFL players, both current and former.

Side note: Steve Smith Sr. might have the most interesting Twitter avatar of any NFL player.

The Raiders and Texans play a Monday Night Football game Nov. 21 in Mexico City. JJ Watt will have to fuel his 9,000-calorie diet with something other than meat.

Send all complaints, compliments, and tips to sportstips@complex.com.