Research support

Nudging adolescents towards plant-based food choices

grant holder
Dr. Hannah Ensaff
university
- Leeds Beckett University, UK.

Subtle changes to the accessibility and presentation of healthy foods are successful in helping school students to make better food choices, according to a study by researchers at Leeds Beckett University funded by Alpro Foundation.

The 18-month research study, published this week in Nutrients journal, found that students were more than twice as likely to choose promoted food items during a trial which used behavioural nudge tactics to encourage the purchase of healthy foods in the school canteen.

The Alpro Foundation-funded research, led by Dr Hannah Ensaff, a Research Fellow in nutrition at Leeds Beckett, saw a number of complementary changes made to the way food was packaged and presented in a secondary school canteen over a six week period and is the first study of its type in the UK.

Collaborating with Associate Professor Matt Homer at the University of Leeds, Professor Pinki Sahota at Leeds Beckett and Helen McLeod, Dietician and School’s Healthy Eating Adviser at Leeds City Council, Dr Ensaff’s research involved the design, implementation and evaluation of ‘nudges’ towards plant-based eating within a secondary school dining environment.

During the six week trial, the researchers found that:

  • Selection of the promoted food items significantly increased, with students two and a half times as likely to select these healthier foods.
  • Students were more than three times as likely to choose a fruit, vegetable or salad item
  • Sales of fruit pots rose from 0.8% to 1.9%;
  • The vegetarian daily specials increased from 0.2% of main foods sold to 0.6%
  • Sandwiches containing salad increased from 0.06% to 1.36%.
  • All healthy food items promoted during the trial increased from 1.4% to 3%.

The study took place within two secondary schools in Yorkshire, one of which was used as a control with the trial taking place in the other.  The school kitchen served 980 students and operated a three-week menu cycle of freshly prepared meals with two daily specials, one of which was a vegetarian option.  The canteen also provided ‘grab and go’ options including pizza, pasta, jacket potatoes, salads, sandwiches, baguettes as well as tray-bakes, hot puddings, fruit and fruit pots.

The researchers made no changes to the food on offer to students and didn’t overtly publicize the changes they made to the packaging and presentation of the food.  The students’ food choices were compared for three periods: a 29 week baseline, a six week trial, then a three week post-trial period. Point of sale data was used to monitor students’ choices through the schools’ cashless payment systems.

The strategies used by the researchers included a variety of subtle changes to the way that food was presented and packaged and included repositioning promoted foods, using disposable pots and trays to serve meals rather than dinner plates, daily posters, window stickers and stickers with smiley faces promoting the designated healthy food options.

Speaking about the study, Dr Ensaff said: “Adolescents’ diet in the UK is generally high in saturated fat and sugar, along with low fruit and vegetable consumption. These choices, typified by low intake of plant-based foods, are mirrored in school canteens, where students commonly bypass freshly prepared nutrient rich meals.”

“School canteens in UK secondary schools are often time-pressured environments – rendering food choice even more susceptible to automatic decision-making.  During our study we found that simple changes to the way food was presented and packaged in the school canteen had a significant effect on students’ selections towards more favourable food options.  Results from our research have shown that ‘nudge’ strategies, which don’t remove the freedom to choose can be really effective in promoting better food choices and changing behaviour.”

Publications:

  1. Ensaff H, Coan S, Sahota P, Braybrook D, Akter H, McLeod H. Adolescents’ Food Choice and the Place of Plant-Based Foods. Nutrients 2015;7:4619-37. free online
  2. Ensaff H, Homer M, Sahota P, Braybrook D, Coan S, McLeod H. Food Choice Architecture: An Intervention in a Secondary School and its Impact on Students’ Plant-based Food Choices. Nutrients 2015;7:4426-37. free online.

Documents

Pictures

Some pictures of the tools used in the research to nudge adolescents to more plant-based nutrition