Time to purge the closet. It seems research supports the age-old adage that horizontal stripes make you look fat. So says one woman's award-winning amateur study.
After research published in 2008 by Dr Peter Thompson, a senior lecturer in psychology at the University of York, 53-year-old Val Watham felt compelled to test drive the theory.
The organizational consultant from Berkshire had 500 people to watch videos of 'average-sized' women wearing various pieces of striped clothing designed by fashion students at the University of the Creative Arts.
Viewers were then asked to rate models in terms of how tall and wide they looked.
Surprise, surprise. Even though Watham's control group could have been bigger, her findings corroborated earlier research. Models in horizontal stripes were perceived as the widest, while those wearing vertical stripes were perceived as the tallest and slimmest.
The research was enough to bag Watham the BBC's Amateur Scientist of the Year award, beating out more than 1,000 contenders.
Second thoughts about the cute black-and-white striped top my husband bought me recently. If only those stripes were facing the other way...
In face of the scientific evidence, will you abide by this and other slimming fashion commandments, or proudly flout it?