Self-control — or lack of it — can have a serious impact on our lives. Poor self-control can lead to feelings of loneliness, while those with higher levels of self-discipline experience states like hunger and tiredness less intensely. Yet despite these obvious benefits, the vast majority of us sometimes experience failures in self-control no matter how hard we try.

Going home from dinner out with a friend or a Sunday family lunch, you may notice you feel slightly more full than you normally do after eating. And while some of this may have to do with how many potatoes your mum insists you eat, new research seems to suggest that there could be something else going on. Researchers analysing dozens of past studies on the “social facilitation” of eating have confirmed that people do tend to eat more when eating in groups than alone — and have come up with several social and psychological mechanisms that could explain our increase in consumption in company.

Food is a fraught thing. What people eat, when they eat it, how much they eat—all of it is subject to scrutiny, both social and scientific. Little wonder, then, that who people eat with seems to influence what they eat. And adding gender to the mix just makes it worse. There’s a whole body of research suggesting that in cultures where female thinness is prized, disordered eating among women can be at least partially attributed to competition for mates.