The effects of increased serving sizes on consumption

The US Food and Drug Administration recently revealed that it is considering modifying the Nutrition Facts Panels required on packaged foods. One proposed change is increasing serving sizes included on labels, which has two potential implications. Larger serving sizes could increase consumption if consumers use the serving sizes displayed as a reference point for their own consumption (McFerran et al., 2010). Alternatively, larger serving sizes that depict increased values of negative nutrients (e.g. calories) could lead consumers to perceive foods as less healthy, thereby reducing consumption (Russo et al., 1986). In study 1 (Online sample, N = 208, Mage = 32, SDage = 12), participants saw pictures of packaged food items and nutrition labels. The labels, depicted either the existing or larger serving size. Across all foods, larger serving sizes led to lower health perceptions. Labels with larger serving sizes were rated as more representative of typical consumption. Study 2 (Online sample, N = 347, Mage = 31, SDage = 10) used the same design as study 1, but required participants to virtually portion foods. While serving sizes did not impact the amount of food consumers portioned, those who saw labels with larger serving sizes estimated that they portioned out more calories. In study 3 (Student sample, N = 198, Mage = 20, SDage = 1), participants were given M&Ms to eat, paired with a nutritional label depicting either the current or a larger serving size, while participating in unrelated surveys. Participants presented with the larger serving size label consumed less than those presented with the current serving size label. Together, the results suggest that the proposed increase in serving sizes on Nutrition Facts Panels could lower consumption of high-calorie foods.