The human body has an internal body clock. Every 24 hours it goes through a circadian rhythm which is an internally driven biological, physiological and behavioural rhythm of alertness and heightened attention in the middle of the day to drowsiness and lethargy in the evening before bed.
Although the circadian rhythm is known to be endogenously driven which means it is relies on internal hormonal levels to instigate alertness and lethargy at appropriate times. External environmental cues can manipulate these natural rhythms including the exposure to light and dark.
It has long been scientifically and medically accepted that people who are exposed to artificial day light such as night workers are more likely to suffer from heart disease, high blood pressure, diabetes and possibly less equipped to cope with stress .
Recent research has examined the effect of mutated forms of the hormone Melatonin, the hormone primarily responsible for maintaining the internal circadian rhythms. The research conducted at Imperial College London reported that a common mutation of the gene for Melatonin can increase the chances of being diagnosed with type 2 diabetes and this chance is enhanced if their bodies are out of synchronisation with the natural light and dark rhythms.
This research highlights the necessity for health and wellbeing to maintain appropriate circadian rhythms each day by waking up and starting the day early after the sun rise and not going to bed too late.