California Code, Business and Professions Code - BPC § 12022.5

Fresh meat or roasts of any kind or cut shall be exposed, advertised, offered for sale or sold on the basis of net weight of the fresh meat or roast only, and any added fat of any kind whatsoever either wrapped within or injected with a larding needle or otherwise inserted in such fresh meat or roast shall be considered as tare weight only.

Notwithstanding the above provision, added fat shall not be considered tare weight if the meat package containing such added fat is clearly and prominently labeled in eight-point type or larger with the term “fat added.”