Argues that although intense sweeteners (IS) such as saccharin and aspartame are perceived by consumers as important aids to dietary and weight control, there is little evidence to support this optimism. The result of dietary surveys comparing food intake or weight change in users and non-users of IS are difficult to interpret because they are likely to be confounded by other differences between these groups. Results from laboratory studies show that reduced-calorie foods and drinks have a reduced capacity to inhibit appetite (reduced satiating power). Therefore the incorporation of IS into the diet cannot be expected to lead “automatically” to a reduction in energy intake. Indeed, if users were to assume that such an effect exists, this might well prove counterproductive. If used wisely, however, IS might facilitate dietary compliance by increasing the range of foods that can be included in weight loss or weight maintenance diets.