Food is an integral part of our life and what and how much we eat crucially affects our health. Our food choices largely depend on how we perceive certain characteristics of food, such as whether it is healthy, delicious or if it qualifies as a salad. But these perceptions differ from person to person and one person's "single lettuce leaf" might be another person's "side salad". Studying how food is perceived in relation to what it actually is typically involves a laboratory setup. Here we propose to use recent advances in image recognition to tackle this problem. Concretely, we use data for 1.9 million images from Instagram from the US to look at systematic differences in how a machine would objectively label an image compared to how a human subjectively does. We show that this difference, which we call the "perception gap", relates to a number of health outcomes observed at the county level. To the best of our knowledge, this is the first time that image recognition is being used to study the "misalignment" of how people describe food images vs. what they actually depict.
Little is known about the relationship between weight status and reward-related brain activity in normal weight humans.We correlated orbitofrontal and anterior cingulate cortex activity as measured by functional magnetic resonance imaging with body mass index in 13 healthy, normal-weight adult women as they viewed images of high-calorie and low-calorie foods, and dining-related utensils. Body mass index correlated negatively with both cingulate and orbitofrontal activity during high-calorie viewing, negatively with orbitofrontal activity during low-calorie viewing, and positively with orbitofrontal activity during presentations of nonedible utensils.With greater body mass, activity was reduced in brain regions important for evaluating and modifying learned stimulus^ reward associations, suggesting a relationship between weight status and responsiveness of the orbitofrontal cortex to rewarding food images. NeuroReport 16:859^ 863 � c 2005 Lippincott Williams & Wilkins.