A high-fat diet over less than 10 days was found to damage the short-term memory of rats used in the experiment from scientists at Oxford University.
The research team studied rats fed a low fat diet, comprising 7.5 per cent of calories as fat, and compared them with rats fed a high-fat junk food diet, with 55 per cent of calories as fat.
It found that after four days the muscles of the rat on the high-fat diet were less able to use oxygen to make energy needed to exercise, causing an increase in heart size.
After nine days, the high-fat rats made more mistakes in a maze, taking longer to complete it. On the other hand, the low-fat rats were running 50 per cent further by this period.
Researchers found increased levels of a protein called uncoupling protein 3 in the rats’ muscle cells. The protein makes the cells less efficient at using oxygen to make the energy required for running.
Andrew Murray, co-author of the study, said: “Western diets are typically high in fat and are associated with long-term complications such as obesity, diabetes, and heart failure yet the short-term consequences of such diets have been given relatively little attention.
“We hope that the findings of our study will help people to think seriously about reducing the fat content of their daily food intake to the immediate benefit of their general health, well-being and alertness.”
Dr Gerald Weissmann, editor of the Federation of the American Societies for Experimental Biology, who published the study, said: “It’s nothing short of a high-fat hangover.”