The influence of taxes and subsidies on energy purchased in an experimental purchasing study.

There is limited research on how taxes and subsidies would influence the energy and nutritional quality of food purchases. Using an experimental analogue purchasing task, we examined the effects of increasing the price of high-calorie-for-nutrient foods or reducing the price of low-calorie-for-nutrient foods by 12.5% and 25% on mothers' purchases of 68 common foods and drinks. Taxing less healthy foods with low nutrient density reduced energy (caloric) intake, while reducing the proportion of fat and increasing the proportion of protein purchased. Subsidizing more healthful foods with high nutrient density increased energy intake, without changing the macronutrient profile of foods purchased. These results favor taxes as a way to reduce caloric intake.