The effects of dietary restraint and portion-control packaging on snack consumption behaviour

The present study investigated the effects of package size on consumption behaviour when either body image or dietary concerns are activated, in restrained and unrestrained eaters. Portion-control packaging has recently emerged under the assumption that carefully-controlled portion sizes help limit consumption of palatable snacks. While there is reasonably good support for this in most populations, recent findings suggest that portion-control packaging may paradoxically increase consumption for restrained eaters (Coelho Do Vale, Pieters, & Zeelenberg, 2008; Scott et al., 2008). Consistent with prior research, we hypothesized that restrained eaters activated for dieting or body image concerns are more likely to deem larger packaged-sized treats as “unacceptable” and decrease intake. Similarly, activated restrained eaters are more likely to deem smaller packaged-sized treats as “acceptable” and thus paradoxically increase intake. However, the present study did not find support for hypotheses. Theoretical reasons as to why results were not what researchers anticipated are proposed.