There is a discussion in the Journal of the American Medical Association for August 18 of a new syndrome, which has been called the "night eating syndrome". It throws light upon an interesting facet of everyday living for some people.
There are claimed to be millions of individuals who raid household refrigerators late at night and consume vast quantities of food while the rest of the family sleeps. There may be some connection between this syndrome and the serious disorder known as bulimia nervosa, in which people have sudden urges to fill their stomachs. The night eating syndrome is characterised by morning anorexia and night insomnia and may be connected with periods of stress and failed efforts to reduce obesity.
A study carried out at the University of Pennsylvania involved volunteers who claimed to be unable to eat in the mornings, to overeat in late evening, and an inability to sleep. They recorded their consumption of food, their nocturnal awakening and their mood at various times of the day. Daily food consumption by the night eaters was about 12,260kJ, compared with about 9,800kJ by the controls. Night eaters had twice as many eating episodes as controls, but during the day their intake of food was less. After 8pm, night eaters continued consuming until after midnight, while eating by controls fell by 85 per cent at the same time of day.
Mood in night eaters deteriorated after about 4pm while that in controls remained unchanged. Nocturnal awakening among the night eaters was far more common than among controls, and half the awakenings were accompanied by eating, whereas those of controls did not involve eating. Nocturnal awakenings were not observed in subjects who were suffering from bulimia nervosa.
In a study of neuroendocrine functions performed in Norway, no instances of sleep apnoea were observed in night eaters or others. The night eaters had a lesser nocturnal rise in plasma melatonin and leptin and higher circadian levels of plasma cortisol than controls. Whether drug treatment to control such effects might be useful in the night eating syndrome remains to be discovered.