Historical increases in the size of commercially available food products have been linked to the emergence of a worldwide obesity crisis. Although the acute effect portion size has on food intake is well established, the effect that exposure to smaller portion sizes has on future portion size selection is yet to be examined.We tested whether reducing a food portion size may 'renormalize' perceptions of what constitutes a normal amount of food to eat and result in people selecting and consuming smaller portions of that food in future. Across three experiments participants were served a large or smaller portion of food. In experiments 1-2, twenty four hours later participants freely selected and consumed a portion of that food. In experiment 3, one week later participants reported on their preferred portion size of that food.