And nutrition expert Sophie Medlin, of King’s College London, believes its high level of the amino acid tryptophan could be the key ingredient behind restful slumber.
She said: “Tryptophan is the biggest influence on melatonin levels, an important hormone which controls our sleep patterns. So a hot chocolate drink or a little bit of chocolate before bed is actually really good for sleep, so long as you don’t over-indulge.”
Women are more likely to have a sweet tooth with 40 per cent admitting they like to eat chocolate before bedtime but only a third of men do so.
They are more likely to enjoy an alcoholic nightcap.
For insomniacs who prefer to stick to savoury, she says that foods high in B vitamins, calcium and magnesium could also have an impact.
She suggests they should munch on cheese, meat, fish, nuts and seeds, dark leafy vegetables and yoghurt.
The survey revealed that a third enjoy crunching crisps, while others dispel the myth that cheese gives you nightmares, with 30 per cent enjoying a snack.
A further 28 per cent love sucking on sweets while others stick to plain and simple bread (26 per cent), the study by bed and sleep specialist Time for Sleep found.