We demand that food manufacturing companies be required to inform us if product size changes on the container

There seems to be a growing tendancy of U.S. Food Mfgs to reduce the size of their products, while keeping the price the same, or actually increasing it. (e.g. a brand of soup used to be $.50 for a 12 oz can, but now costs $.65 for a 10 oz can of the same product) This makes it very difficult for us to manage our food costs. We would like to either be told up front that it is a smaller product, or just charged more for the same size product.