Abstract
Larger portion sizes increase energy intake, yet it is unclear whether single-serving packages can reduce intake. This study examined the effects of providing breakfast foods in single-serving packages and nonportioned packages on energy intake of these foods during an 8-week behavioral weight-loss program. In fall 2005, 19 adults (mean body mass index [calculated as kg/m(2)]=31.8+/-4.0) were randomized to conditions that provided foods in single-serving packages (Single-Serving) or in nonportioned packages (Standard). Overall amounts and types of foods provided were consistent across conditions: cereal and peaches (weeks 1, 3, 5, and 7) and applesauce and cheese (weeks 2, 4, 6, and 8). Participants were instructed to eat one serving of each food for breakfast and not to consume the provided foods at other times. Mean daily energy intake of the provided foods was the primary dependent variable. The Single-Serving group ate less energy from the combined pairs of foods provided together as compared to Standard (cereal and peaches, 117.0+/-3.2 kcal/day vs 143.5+/-39.3 kcal/day; P<0.05 and applesauce and cheese, 174.2+/-13.5 kcal/day vs 199.0+/-29.4 kcal/day; P<0.05). This effect was a result of less energy consumed from cereal and applesauce in Single-Serving compared to Standard conditions (cereal, 80.2+/-2.9 kcal/day vs 106.3+/-22.9 kcal/day; P<0.01 and applesauce, 44.5+/-0.6 kcal/day vs 59.3+/-5.0 kcal/day; P<0.01), with no differences in energy consumption for peaches and cheese (P>0.10). This suggests that single-serving packages may help reduce energy intake at breakfast within the context of a behavioral weight-control program.