Lots of discussion about this study:
Findings from Sesame Workshop’s initial “Elmo/ Broccoli” study indicated that intake of a particular food increased if it carried a sticker of a Sesame Street character. For example, in the control group (no characters on either food) 78 percent of children participating in the study chose a chocolate bar over broccoli, whereas 22 percent chose the broccoli. However, when an Elmo sticker was placed on the broccoli and an unknown character was placed on the chocolate bar, 50 percent chose the chocolate bar and 50 percent chose the broccoli. Such outcomes suggest that the Sesame Street characters could play a strong role in increasing the appeal of healthy foods.So put an Elmo sticker on good food and apparently demand goes up. Of course, one wonders what sort of chocolate bar it was that caused 22 percent of children exercising free will to choose broccoli over it. On the other hand that could be some broccoli. Apparently, further investigation is needed.
What I would like to see is the impact on the quantity consumed and not necessarily the type of food. For instance, does a 'large' packet of broccoli with Elmo get chosen over a 'small' packet without it? And does it get eaten. Similarly, does a 'small' packet of chocolate with Elmo get chosen over a 'large' one without it? And can you actually repeat this on a daily basis rather than just a once off? Surely, there are diminishing returns to Elmo.