A new study has revealed why we fall into a ‘food coma’ after sitting down to eat a huge Christmas lunch. It was once believed that the sleepiness experienced after eating a turkey dinner was down to the amino acid in the bird, tryptophan.
However, researchers now say that is not true as turkey contains no more of the acid than either chicken or beef. In fact, nuts contain more. Now, new research which was carried out with fruit flies may provide some of the answers.
Scientists found that, just like humans, fruit flies tend to sleep off large meals. There were also some foodstuffs which made them feel more drowsy than others.
Professor William Jafrom, who is from the Department of Metabolism and Aging at Scripps Florida, said: “Studies on the ‘food coma’ effect in humans have been hit or miss. Sleep is really hard to study in people since very few can sleep normally when they’re being watched.”
While he admitted that flies have different sleep patterns to people, he said that the study had still provided valuable information which could be applied to humans. He added that in fruit flies there was an interation between sleep and metabolism.
The professor added: “Flies suppress sleep or increase their activity when starved. However, the acute effects of food consumption on sleep have not yet been tested, largely because there was no system available to do so.”
The flies slept for 20 to 40 minutes longer after eating large portions which were rich in protein and salt. Meals with lots of sugar in them did not provide the same levels of drowsiness.
Prof Jafrom added: “If you want to avoid the ‘food coma’ you might want to rethink your menu.” However, it is unlikely that families will forego their usual Christmas turkey in case they feel sleepy.