Another reason for the trend back to open kitchens (and a foundation of the "kitchen object" philosophy) is changes in how food is prepared. Whereas prior to the 1950s most cooking started out with raw ingredients and a meal had to be prepared from scratch, the advent of frozen meals and pre-prepared convenience food changed the cooking habits of many people, who consequently used the kitchen less and less. For others, who followed the "cooking as a social act" trend, the open kitchen had the advantage that they could be with their guests while cooking, and for the "creative cooks" it might even become a stage for their cooking performance.