Research by Dr Andrew Smith, director of the health psychology research unit at the University of Wales, Cardiff, has found that the 'post-lunch dip' in alertness that can last for two hours can be countered by coffee.
He said: 'This is good news for coffee . . . a couple of cups of strong coffee can largely relieve the post-lunch drop in alertness. We don't know what the long-term effects of missing lunch are, but sometimes it might be beneficial if people need a high level of concentration.'
His seven years of studies on the effects of food on mood and mental abilities led him to conclude that some food habits work to our advantage.
Measurements of alertness after lunch revealed a bigger slump in concentration in calmer people. Those who are anxious are less affected, possibly because they live in a higher state of arousal, Dr Smith said. His results showed that what people ate for lunch had little effect.
Research on the effect of breakfast found that it was good for the memory but bad for logical reasoning such as mental arithmetic. But again, a cup of coffee for elevenses will bring the mental skills up to normal. Dr Smith's studies of the effects of dinner revealed no interesting changes in people's abilities. But coffee after dinner was only advisable for those who wanted to stay awake late.