Data in literature show that body weight in adults and children seems to be related to portion sizes more than to food choices and people are more reluctant to give up favourite foods than to reduce portions. So several scientific societies in USA have recently emphastzied the need to select appropriate portion sizes. At the same time, studies on cognitive strategies show that the best method to help people to remember how much they eat is visualisation/comparison to tridimensional visual aids. So a new technique for evaluating portion sizes, based on comparison of portions to volume of usual objects (baseball, dice, deck of cards) appeared in the last years, in nutritional surveys and food educational projects. Our team, since 1990, appointed a volumetric assessment based on comparison of foods to the fist, palm, fingers of the examined subject; this system has been experienced with success for a long time both in individual dietetics and in food educational projects or surveys. Since the interest for this new technique is rising, the aim of this review is to introduce the method and to delineate the applications in nutritional surveys or educational projects in national and international literature. This method, simple practical and intelligible, seems to be addressed to a wide development in the future.