There is not yet an evolutionary mechanism to help us overcome the lure of sweet, fatty and unhealthy food and avoid becoming overweight for understandable and sensible reasons, according to researchers at the University of Exeter in UK.
This is because in our past being overweight has not posed a significant threat to survival compared to the dangers of being underweight.
The urge to maintain body fat is even stronger in winter when food in the natural world is scarce.
This explains why we enjoy eating so much at Christmas, and our New Year's resolutions to lose weight usually fail, the researchers said.
They used computer modelling to predict how much fat animals should store, by assuming that natural selection gives animals, including humans, a perfect strategy to maintain the healthiest weight.
The research showed that there is usually only a small negative effect of energy stores exceeding the optimal level, so subconscious controls against becoming overweight would be weak and easily overcome by the immediate rewards of tasty food.

The research was published in the journal Proceedings of the Royal Society B.


Latest News from Lifestyle News Desk