Crash diets 145;may reduce lifespan146;: Study

8220;Applying this to humans, it would only occur in children and teenagers. But it would be for extreme switches in diet. Just skipping lunches would not have any effect, but if they had several weeks of one diet followed by several weeks of the extreme opposite, then there could be an effect,8221; lead researcher Prof Neil Metcalfe said.

In their study, the researchers also found that the difference in lifespan was not a consequence of more rapid ageing but an increase in the risk of sudden death.

8220;The fish on the fluctuating diet put just as much effort into breeding 8212; the males became brightly coloured as usual and females produced the normal number of eggs. However, on average their lifespan was three-quarters that of animals eating a constant amount every day.

8220;It seems that uneven growth, due to the fluctuation in the amount eaten per day, is responsible for the increase in the risk of sudden death. This is possibly because the body tissues are more likely to have imperfections due to growth spurts,8221; the 8216;BBC News8217; portal quoted Prof Metcalfe as saying.

Similar results would most likely be seen in other animals with short lifespans that grow throughout their lives, said Prof Metcalfe.