Weighting instrument for dietetic use

Weighing instrument having a receiver tray for foodstuffs movable with respect to a body and an index mark displaceable along a predetermined path on a housing carried by said body in front of a first scale marked in weight and fixed with respect to said housing as well as in front of a plurality of second scales marked in at least one magnitude involved in dietetics and borne by a flexible strip on which they are succeeded by categories of foodstuffs, this magnitude being proportional to the weight of foods and the position of said flexible strip with respect to said housing being adjustable at will to operate selectively in association with the index mark that of its second scales which corresponds to the category of foodstuff to be weighed, the flexible strip being guided by a plurality of parallel rollers of which one at least is provided with control means enabling it to be rotated selectively to make the various second scales move in front of the index mark along a path substantially perpendicular to said predetermined path of said index mark, the housing including means for receiving selectively and removably, between said predetermined path of the index mark and the flexible strip, one card provided with third scales arranged to cooperate with said index mark and selected from a plurality of cards each corresponding to a particular foodstuff.