The study carried out by amateur scientist Val Watham demonstrated that horizontal stripes make people appear wider, while vertical stripes make people appear taller.
Watham's experiment, which involved dressing models in a variety of striped designs and asking volunteers to rate their appearance, won the BBC's Amateur Scientist of the Year award, beating over 1,000 other entrants.
The purpose of the award is to give amateurs the chance to go through the process of "being a scientist" by producing experiments under the guidance of a professional mentor.
Watham's research challenges the past findings of her scientific mentor Dr Peter Thompson of the University of York.
Dr Thompson had earlier showed that horizontal stripes make you look taller and thinner due to a visual effect called the Helmholtz illusion, the BBC reported.
When she saw these findings reported in the press, she became sceptical. She felt the line drawings Dr Thompson used in his experiment weren't realistic. So she applied to repeat his experiment using real people wearing real clothes.
First year fashion students at the University of the Creative Arts designed and produced 15 outfits. They were then filmed modelling the clothes in a catwalk shoot.
Five hundred visitors to the Edinburgh Science Festival watched these videos, and rated how tall and wide each model looked in different outfits.
The results were surprising, given Dr Thompson's previous research. The public rated the models in horizontal stripes as more wider, while those in vertical stripes appeared taller.
The judges described it as "a lovely idea which was well executed, had clear results and leads on to further research. You can't ask more from a science experiment".
The work also proved another fashion dictum: models who wore all black outfits were deemed to be the slimmest of all.
Runners-up of the award included Izzy Tomlinson, 18, a student from Shropshire, who found that women are more sensitive to the sound of nails down a blackboard.