Except for immediate consumption on the premises where sold, or as 1 of several elements comprising a ready-to-eat meal sold as a unit for consumption elsewhere than on the premises where sold, all meat, meat products, poultry, whole or parts, and all seafood except shellfish, offered or exposed for sale or sold, as food shall be offered or exposed for sale and sold by weight. When meat, poultry or seafood is combined with or associated with some other food element or elements to form either a distinctive food product or a food combination, such food product or combination shall be offered or exposed for sale and sold by weight, and the quantity representation may be the total weight of the product or combination, and a quantity representation need not be made for each of the several elements of the product or combination.