If you – like almost everyone else in the country – vowed to leave the excesses of the long weekend behind you and embark on a healthier way of life today, you may have been stunned to see your good intentions fall apart around the 3pm mark.

But before you beat yourself up for not making it through one measly day without a chocolate fix, it's worth remembering that this perceived failure comes down to more than just a lack of willpower.

Researchers from Liverpool University and Flinders University in Adelaide, Australia have discovered that our brain's perception of junk food changes radically as the day progresses leaving us more susceptible to a mid-afternoon binge.

Conducting a psychological experiment on more than 300 women aged between 17 and 25, researchers established that junk food is more often associated with negative experiences at the start of the day – something which gradually changed as the subjects made their way through the day.

According to a report in RedOnline, the groups were shown a variety of images and words – some of which were food-related, some of which were not – and as the day progressed food-related words and images were rated more favourably by participants.

Further to this, it was established that subjects subconsciously associated certain foods with certain times of the day meaning that cravings kicked in due to the body's inclination to associate junk food with particular points in the 24-hour clock.

"Individuals who participated later in the day tended to implicitly evaluate unhealthy snack food as more positive than those who had participated earlier in the day," the study explained.

So, when you find yourself raiding the office biscuit tin halfway through the afternoon, you can just blame that damn body clock of yours.

The study was published in the Food Quality and Preference journal.