Dieters lose will as darkness falls

Binge eaters, vegetarians, alcoholics and reformed smokers are all at their most vulnerable when night falls.

Binge eaters, vegetarians, alcoholics and reformed smokers are all at their most vulnerable when night falls.

Psychologists have found that dimmer lighting affects behaviour and makes people less inhibited, undermining their self-discipline and control. Thus, bulimics are more likely to gorge themselves, dieters more prone to eat cakes, vegetarians more at risk of succumbing to eating meat, and ex-smokers more vulnerable to having a cigarette.

In research reported in the current issue of the journal Personality, psychologists looked at a group of people and found that so-called night people, those who both go to bed and wake up late, are more likely to suffer with bulimia.

They say that bulimic binge eating is not only more common at night than during the day, but also more prevalent in winter months with longer nights. Bulimics are also more likely to binge with the lights turned down low.

One explanation is that the lack of light has an effect on behaviour.

"Exposure to dimmer lighting promotes general behavioural disinhibition, thus undermining self-regulation, control and adherence to one's dietary standards, resulting in the disinhibited eating that is the hallmark of bulimia. Dimly lit settings increase the probability of counter-normative behaviours that are more successfully inhibited under brighter light," says the report.

It adds: "Existing evidence demonstrates that exposure to dimmer lighting decreases self-awareness."