Table 1 Summary of studies included in this narrative synthesis

SHELf

Australia

RCT

Second largest national supermarket chain

2 stores

574 women

Four study conditions:

1) 20% price-reduction on fruit, vegetables, water and low-calorie beverages

2) Tailored skills-based behaviour-change intervention

3) Combined skill-building and price-reduction

4) Control group

Intervention duration: 3 months

Ball et al., 2011, BMC PH

Ball et al., 2015, AJCN

Olstad et al., 2016, IJBNPA

Le et al., 2016, SSM

Healthy Checkout Counter studies

The Netherlands

Quasi experimental design (3 experiments)

Largest national supermarket chain

Three study components:

1) 24 stores (15 intervention, 9 control)

2) 2 stores

3) 1 store

Three study components:

1) Increased availability and prominent positioning (check-out counter) of healthier snacks

2) Increased availability and prominent positioning (check-out counter) of healthier snacks in combination with pricing strategies

3) Removal of unhealthy products at check-out counter and replaced with healthier products

Intervention duration: 2 months

Huitink et al., 2020, BMC Public Health

Huitink et al., 2020, Int. J. Environ. Res. Public Health

Healthy Supermarket Coach studies

The Netherlands

Quasi experimental design (2 experiments)

Largest national supermarket chain

4 supermarkets (3 intervention, 1 control) and 4 schools (3 intervention, 1 control)

Study conditions:

1) Peer education workshop for adolescents by supermarket staff

2) Control group

Intervention duration: 1 week

Huitink et al., 2021, Health Educ Behav

Social norm nudges in supermarket trolleys

The Netherlands

Quasi experimental design

Largest national supermarket chain

1 store

Intervention component:

1) Shopping trolley placemat with a social norm message about vegetable purchases and a designated place to put vegetables

Intervention duration: 1 weekend day

Huitink et al., 2020, Appetite

Supreme Nudge

The Netherlands

Parallel cluster-RCT

National (cooperative) supermarket chain

12 stores (6 intervention, 6 control)

~ 400 adults aged 30–80 years

Study conditions:

1) Nudging (prominent positioning, labelling, healthy check-outs, healthy baskets, healthy end-of-isles

2) Pricing (decreased prices of healthy foods and increased prices of unhealthy foods) strategies

3) Control group

Intervention duration: 12 months

Lakerveld et al., 2018, BMC Public Health

Stuber et al., 2020 Nutrition Journal

Middel et al., 2021 IJHPM

Stuber et al., 2022 Nutrition Journal

WRAPPED (pilot)

UK

Prospective matched controlled cluster design

National discount supermarket chain

6 stores (3 intervention, 3 control)

150 women aged 18–45 years

Study conditions:

1) Removal of unhealthy products from checkouts and aisle-ends opposite and replaced with non-food items and water

2) Increased availability and prominent positioning of fruit and vegetables

3) Control group

Intervention duration: 6 months

Vogel et al., 2021, Plos Med

Shand et al., 2021, SSM

Dhuria et al., 2021, BMC PH

WRAPPED (full scale)

UK

Prospective matched controlled cluster design

National discount supermarket chain

36 stores (18 intervention, 18 control)

1620 women aged 18–60 years

Study conditions:

1) Increased availability and prominent positioning (front of store) of fresh fruit and vegetables section

2) Control group

Intervention duration: 6 months

Vogel et al., 2020, BMJ Open

Muir et al., 2023, BMC Medicine