How nutrition information leads you to buy more

Have you ever been to the supermarket and chosen foods based on nutrition labels? If so, be cautious, because the nutrition values you see on labels can substantially differ based on the recommended serving size, with undesired consequences for your purchase behavior. According to a new research published in the Journal of the Association for Consumer Research, smaller recommended serving sizes on nutrition labels can unknowingly lead you to buy more than you need.

Consumer researchers from Germany, who conducted the research, found that shoppers bought more yogurt when the recommended serving size was smaller. In their study the researchers analyzed millions of food purchases in European supermarkets before and after the introduction of a front-of-pack nutrition label. The data covered two years and 61 products from a healthy (yogurt) and unhealthy (cookies) category. "Smaller recommended serving sizes will let all nutrition values on the label appear smaller too, independent of the product's actual nutritional composition" says lead author Dr. Ossama Elshiewy from the University of Goettingen. Shoppers, who read nutrition labels, tend to ignore the smaller recommended serving size and think that these products are healthier than others. "The problem is that people are comparing calorie information that is not comparable," Dr. Elshiewy adds.

Co-author Dr. Steffen Jahn, also from the University of Goettingen, suggests to always check the recommended serving size when reading nutrition labels. "This will prevent you from underestimating nutrition amounts and will make your choices healthier."