A human randomised trial into the impact of eating high saturated fat, high added sugar diet showed a decline in memory tests after one week and a greater desire to eat junk food after finishing a meal. 110 lean healthy adults in their 20’s who generally ate a good diet were randomized into a control group eating their normal diet and the Western-style diet group consuming a diet rich in ultra-processed foods. The Western-style diet group showed a decline in cognitive function within 7 days.
Richard Stevenson, a professor of psychology at Macquarie University in Sydney said “This research has provided data to support detrimental effects on both memory and appetite control after just one week of an energy-dense diet and may suggest a link between poor diet and impairment of the hippocampus, a key memory and appetite-associated brain region. The mechanisms at work remain to be elucidated and will require further research with the application of more sophisticated neuroimaging methods.”
“Demonstrating that processed foods can lead to subtle cognitive impairments that affect appetite and serve to promote overeating in otherwise healthy young people should be a worrying finding for everyone,”
The full research article published in The Royal Society Open Science can be viewed here; https://doi.org/10.1098/rsos.191338
Ian Sample Science editor of The Guardian reports on the findings here; https://www.theguardian.com/science/2020/feb/19/researchers-find-a-western-style-diet-can-impair-brain-function
Stevenson Richard J., Francis Heather M., Attuquayefio Tuki, Gupta Dolly, Yeomans Martin R., Oaten Megan J. and Davidson Terry Hippocampal-dependent appetitive control is impaired by experimental exposure to a Western-style diet7R. Soc. open sci. https://doi.org/10.1098/rsos.191338