How Health Claims Bias Portion Size Estimations and Lead to Obesity

Pierre Chandon, INSEAD, France
Brian Wansink, Cornell, USA
We test a halo explanation of the paradoxical rise in obesity and in the consumption of objectively healthier foods. In two field studies and two laboratory experiments, we find that calorie estimations are primed by the vice or virtue positioning of fast-food restaurant brands and menus (e.g., Subway vs. McDonald’s). Such health halos lead people to indulge in higher-calorie side orders and desserts when the main sandwich has a healthy prime than with an unhealthy one. As a result, “healthy” fast-food meals can contain more calories, but be perceived as containing fewer, than unhealthy meals. Fortunately, a consider-the-opposite estimation strategy eliminates the effects of health claims on portion size estimations and on subsequent consumption decisions.
[ to cite ]:
Pierre Chandon and Brian Wansink (2007) ,"How Health Claims Bias Portion Size Estimations and Lead to Obesity", in NA - Advances in Consumer Research Volume 34, eds. Gavan Fitzsimons and Vicki Morwitz, Duluth, MN : Association for Consumer Research, Pages: 647-650.