Study co-authors Ryan Elder and Jeff Larson, both marketing professors in Brigham Young University's Marriott School of Management, said a friend's obsession with posting pictures of their burgers and salads on Instagram, Pinterest or Facebook might ruin the appetites of those viewing the pictures.
Larson and Elder recruited 232 people to look at and rate pictures of food. In one study, half viewed 60 pictures of sweet foods such as cake, truffles and chocolates, while the other half looked at 60 pictures of salty foods such as potato chips, pretzels and french fries.
After rating each picture based on how appetizing the food appeared, each participant finished the experiment by eating salty peanuts. Participants then rated how much they enjoyed eating the peanuts.
Those who looked at the salty foods ended up enjoying the peanuts less even though they never looked at peanuts, just at other salty foods, the researchers said.
Elder and Larson said what happened was the over-exposure to food imagery increased people's satiation. Satiation was defined as the drop in enjoyment with repeated consumption, or the fifth bite of cake was less enjoyable than the first.
The findings were published in the Journal of Consumer Psychology.