The US-based research suggests that restricting certain the sale of large portions of food and drinks may in fact be counterproductive, because it leads consumers to buy more of a smaller size.
Writing in PLoS One, researchers from the University of California, San Diego, tested the effects of limiting sugary drink sizes on people's soda consumption by offering them different 'menu' deals. They found that when participants made choices on which soda to buy, they bought significantly more ounces of soda with bundles than with varying-sized drinks.
"Total business revenue was also higher when bundles rather than only small-sized drinks were sold," said the researchers - led by Brent Wilson.
Wilson said that regulation on serving sizes "may have unintended consequences that policy makers need to consider."
"Our research suggests that businesses have a strong incentive to offer bundles of soda when drink size is limited," said the research team. "Restricting larger-sized drinks may have the unintended consequence of increasing soda consumption rather than decreasing it."
Study details
Wilson and his colleagues tested the effects of limiting sugary drink sizes on people's soda consumption by offering them three kinds of menus.
The first menu offered 16 , 24 or 32 ounce sized individual drinks, while a second gave them the choices of a 16 oz. drink, or bundles of two 12 ounce drinks or two 16 ounce drinks. A third menu offered only individual 16 oz. drinks.
When participants made choices from these menus - as they would in a fast food restaurant or a shop - people bought more soda from the menu with packs of 12 oz. or 16 oz. drinks than they did when offered individual sodas of different sizes.
As a result, Wilson suggests that when drink or food serving sizes are limited, industry may have a strong incentive to offer packs of several smaller servings rather than only individual servings.
"These results show that businesses should earn significantly more revenue when bundles are offered," they said.
Source: PLoS One
Published online ahead of print, doi: 10.1371/journal.pone.0061081
"Regulating the Way to Obesity: Unintended Consequences of Limiting Sugary Drink Sizes"
Authors: Brent M. Wilson, Stephanie Stolarz-Fantino, Edmund Fantino