Subconscious human desire to overeat during winter identified

A subconscious evolved desire to overeat during the cold winter months has been identified in humans by UK researchers.

The University of Exeter study 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.

It indicated that animals do have a target body weight above which it loses weight and below which it tries to gain weight. However, simulations showed that since there is usually only a small negative effect associated with energy stores exceeding this level, subconscious controls against becoming overweight are weak and easily overcome.

Because in the past being overweight has not posed a significant threat to survival – compared to the danger of being underweight – people find it difficult to overcome the immediate rewards of consuming sweet, fatty and unhealthy food, especially in winter.

Dr Andrew Higginson of the College of Life and Environmental Sciences at the University of Exeter said: "You would expect evolution to have given us the ability to realise when we have eaten enough, but instead we show little control when faced with artificial food."

This helps offer an explanation why people usually eat so much at Christmas and find it so difficult to adopt a healthy diet at the New Year.