Health halos driven by branding or by marketing, health or nutrition claims do not simply change expectations but can act as a placebo and change post-intake evaluations and consumption. Robinson et al. (2007) found that children thought the same food tasted better when it was branded McDonald’s. Raghunathan et al. (2006) found that a smoothie was judged to taste better when described as a product “generally considered healthy”. Lee, Frederick and Ariely (2006) found that adding vinegar improved the taste of beer, but only when it was described as a special ingredient, not when described as vinegar. Interestingly, the description had no effect when it was revealed after tasting, suggesting that ingredient branding affected preferences by influencing the experience itself rather than by acting as an independent negative input or by modifying retrospective interpretation of the experience. Marketing descriptions can even influence biological responses. Crum et al. (2011) found that descriptions of the same milkshake as either “indulgent” or “sensible” influenced physiological atiation as measured by gut peptide ghrelin levels. Neuroimaging studies (Plassmann et al. 2008) have shown that marketing actions influence not just self-reported liking but also its neural representations, suggesting that these effects are not merely influenced by social desirability when reporting subjective experience.
Health halos influence the volume of food consumption and can lead to overeating, defined as people eating more without being aware of it. For example, one study found that adding adjectives like “succulent” or “homemade” boosted sales by up to 28% (Wansink, van Ittersum and Painter 2005). Provencher, Polivy and Herman (2008) noted a 35% greater intake of a cookie described as a healthy “oatmeal snack” rather than an indulgent “gourmet cookie”, regardless of the weight consciousness or dietary restraints of the participant. When Chandon and Wansink (2007a) asked people to imagine that they had received a coupon for either a McDonald’s Big Mac (containing 600 calories and generally considered unhealthy) or a coupon for a foot-long Subway sandwich (a chain generally considered healthy, even though this particular sandwich contains 900 calories), participants ordered 111 calories worth of dessert and sodas to go with the “healthy” sandwich versus 48 calories with the “unhealthy” burger. … In another study, Wansink and Chandon (2006a) found that labeling both “healthy” and “unhealthy” foods as “low fat” reduced calorie estimation by 20% to 25%, and increased what was considered to be the “appropriate serving size” by 20%. More importantly, we found that labeling chocolate candies as “low fat” increased consumption during one meal occasion by 16% among normal-weight people and by 46% among overweight individuals, but had no effect on their estimates of the number of calories that they had consumed.
The author points out that these reactions do vary by type of consumer. It also turns out that you can influence how heavy the consumer thinks a package is by changing the placement of the image of the product on the package: lower means heavier. But possibly most significant is that consumers have no idea this is happening:
Remarkably, people do not believe that packaging influences how much they eat and are largely unaware when it does. … Labeling chocolate candies as “low-fat” increased actual calorie intake by 46% among overweight people but increased their perceived calorie intake by only 8%. Finally, people overlooked up to 50% of the quantity increase in large meals and packages despite their best effort . These effects stand in contrast to other marketing actions like price change (which influence consumers through conscious decisions) or advertising (which consumers know is trying to persuade them) – persuasive attempts that are anticipated by adult consumers.