- Start date: 1 September 2015
- End date: 31 January 2019
- Funder: BBSRC
- Primary investigator: Dr Tang Tang
National survey data for the UK shows that portion sizes of some energy dense foods (foods more than 2.5kcal/g) are associated with overweight and obesity. The term ""portion distortion"" is now commonly used to reflect changes in portions of foods offered outside the home over the last 20 years. This proposal sets out to challenge the portion size effect by testing a variety of environmental strategies to ""downsize"" portions offered to infants and selected by pre-schoolers and adolescents.
The first study will record typical portion sizes of high energy snacks offered to infants aged 24-36m then test the effect of replacing or reducing portions served of these foods within a pilot randomised control trial (RCT).
The second study will involve systematically changing meal item amounts served in nurseries using variety and palatability to offset the portion size effect on self served amounts in pre-schoolers. The third study examines the feasibility and acceptability of using "nudging" to promote smaller portions of snacks in adolescents using social media and digital technologies for sharing social norms of portions. The fourth study uses direct observations in households with infants and pre-schoolers to identify packaging solutions matched to family needs to adjust portion sizes for family members. The final part of the project will provide evidence to recommend ways that stakeholders such as families, childcare workers, healthcare professionals, industry and policymakers can apply downsizing strategies to support healthy portion control.
Publications and outputs
Tang T, Wang W, Croden F, Vazirian M, Hetherington M. 2020. “Wrap healthy snacks with cool packaging” - A qualitative study of mothers’ portion size strategies for their children. Appetite. 147. Available online via DOI and White Rose Research Online.
Hetherington, M.M. and Blundell‐Birtill, P., 2018. The portion size effect and overconsumption–towards downsizing solutions for children and adolescents. Nutrition bulletin, 43(1), pp.61-68. Available online.
Hetherington, M.M., Blundell-Birtill, P., Caton, S.J., Cecil, J.E., Evans, C.E., Rolls, B.J. and Tang, T., 2018. Understanding the science of portion control and the art of downsizing. Proceedings of the Nutrition Society, 77(3), pp.347-355. Available online.