Lack of sleep doesn’t just affect your ability to enjoy life - it can also take a heavy toll on your health. While energetic twentysomethings might not show any ill-effects of repeated late nights, as we age insufficient rest has a dramatic effect on our looks, too.

Brad Pitt recently admitted that six children means virtually no sleep - and it’s clear from his exhausted appearance that he wasn’t joking. But the ever-glowing J-Lo (below) claims to get at least eight hours a night, which may explain why she appears ten years younger than her real age.

Recent research discovered that sleep deprivation has a similar hormonal effect to the ageing process and may even increase the likelihood of age-related diseases. Eve Van Cauter, the scientist who led the study, says: ‘We suspect sleep loss may not only hasten the onset, but could also increase the severity of ailments such as diabetes, hypertension, obesity and memory loss.’

Other studies have shown that sleep deprivation produces a stress reaction in the body, raising levels of cortisol, the stress hormone, and glucose, which can indicate a higher risk of heart disease and strokes. Even more worryingly, women regularly sleeping for fewer than five hours a night had a 45 per cent higher risk of developing heart disease. Interrupted sleep can also affect blood pressure (which usually falls during the night) and leave us vulnerable to colds and flu.

A study from the European Sleep Research Society found that people who were deprived of sleep were also more likely to be rated as less attractive and with poorer skin tone. That may be because during deep sleep, new skin cells are produced. The reason so many of us feel and look ten years younger after a holiday is because, for once, we’ve had enough sleep.

There’s little point spending a fortune on face cream and gym membership to keep yourself youthful, then, if you’re only getting six hours’ rest a night.