Many obesity and nutrition experts have been pushing for governments to adopt "fat taxes" that would raise the price of unhealthy food in order to encourage better eating habits.
Now, researchers in Britain have determined just how much prices would have to go up to make a difference: 20 per cent.
A new paper published in the British Medical Journal also says a corresponding subsidy on the price of fruits and vegetables would have to be introduced in order to see a shift in how people eat.
The Guardian notes in its story on the study that in order to be effective, "fat taxes" should target a wide range of unhealthy foods, not just select items such as pop.
The food industry has long argued that taxing unhealthy food is an irresponsible policy that doesn't help consumers.
But many nutrition experts say fat taxes are needed to combat the tidal wave of cheap, readily available unhealthy food.
They say cheap junk food is of particular concern for low-income individuals, who may have trouble affording healthier options but could easily afford pop, chips or fast food meals, which typically cost only a few dollars.
While this study has found that steep price increases for junk food, combined with fruit and vegetable subsidies, could shift eating habits, other research has found the results of such campaigns to be inconsistent.
Similarly, research has questioned whether "food deserts" – areas where there are few healthy options but an overwhelming amount of fast food restaurants and convenience stores – actually exist.
Would a 20-per-cent tax on junk food stop you from buying it?