Blame it on the crowd

From a University of Toronto study.

Socially informed perceptions of which foods are appropriate to eat,
when they should be eaten and how much should be consumed have a
greater impact on our food intake than feelings of hunger or fullness,
says a University of Toronto review paper published in Physiology & Behavior

“It’s an insidious effect,” Herman (the author) says. “People are often rudderless
in eating situations and they look to the activity of others, their own
previous behaviour or other social cues to guide them and thereby
consume more than they need. Frequently, eating occurs within what we
have termed a zone of biological indifference, in which the individual
is neither genuinely hungry nor genuinely sated. Without any particular
biological reason to start, continue or stop eating, we are
particularly vulnerable to socially based influences.”