FAB RESEARCH COMMENT:
This human randomised controlled trial assessed the effects in healthy young adults of just one week of eating a modern western-style or 'junk food' diet - i.e one rich in ultra-processed foods, and high in both sugar and fat as well as artificial additives - compared with a healthy diet of mainly whole or minimally processed foods.
Relative to the control diet, consuming the western-type diet even for this short time period led to
- poorer appetite control (assessed by self-rated cravings for junk foods even when already feeling full), and
- a decline in learning and memory on tests of hippocampal functioning
These findings are consistent with what has already been well-documented in animal studies - namely that consuming a high-sugar, high-fat western-type diet:
- impairs the ability to prevent overeating (and therefore causes weight gain and associated metabolic problems), and
- also damages the hippocampus (a brain structure critical for working memory and spatial memory, among many other functions).
For an accessible summary of this research, see the associated news item and FAB comment: