How Communicating Misleading Information Dilutes Public Understanding of Weight Loss Mechanisms

The biomedical literature describes clearly the direct mechanisms influencing weight gain, but broader public discourse on the subject is rife with misleading claims about the factors that cause people to gain or lose weight. We examine how such misleading claims can dilute accurate information to the point that people arrive at poor judgments about the direct causes of weight gain. We adapt the conventional experimental paradigm used in dilution research (Nisbett, Zukier, & Lemley, 1981) to measure the effect of different information levels of dilution. We use a pair of online survey experiments to distinguish the effects of receiving distractingly plausible information versus raw information overload. These experiments also probe the limits of the dilution effect by using a large national sample of participants who vary by their health information efficacy and other potential moderators. Results suggest that public confusion about weight loss may stem from a dilution effect, which remains constant across a wide range of subgroups one might otherwise expect to resist it.