Beyond simply feeling decrepit, perception of being older can affect health by encouraging unhealthy eating and reducing exercise

Two nights of broken sleep are enough to make people feel years older, according to researchers, who said consistent, restful slumber was a key factor in helping to stave off feeling one’s true age.

Psychologists in Sweden found that, on average, volunteers felt more than four years older when they were restricted to only four hours of sleep for two consecutive nights, with some claiming the sleepiness made them feel decades older.

The opposite was seen when people were allowed to stay in bed for nine hours, though the effect was more modest, with participants in the study claiming to feel on average three months younger than their real age after ample rest.