This is incorrect. Beef takes a ton of food and releases a good bit of greenhouse gases but nowhere near a ton per kg of meat. Here's a study looking at multiple other studies on the CO2 equivalent greenhouse gases per kg of beef. In particular you'll want to look at page 85.

https://web.archive.org/web/20070709233421/http://www.defra....

That gives a range from 32.3kg per kg of beef to 15kg per kg of beef.